上午10:17 | | | L.I. Rozonoer | | | quant-ph updates on arXiv.org |

The hypothesis of the random flow of time is considered. To do this, the concepts of microscopic random time and macroscopic mean time, as well as random modular time are introduced. The possibilities of experimental verification of the hypothesis of the random flow of time are discussed.

Quantumness Beyond Entanglement: The Case of Symmetric States. (arXiv:2110.11361v1 [quant-ph])

上午10:17 | | | Aaron Z. Goldberg, Markus Grassl, Gerd Leuchs, Luis L. Sánchez-Soto | | | quant-ph updates on arXiv.org |

It is nowadays accepted that truly quantum correlations can exist even in the absence of entanglement. For the case of symmetric states, a physically trivial unitary transformation can alter a quantum state from entangled to separable and vice versa. We propose to certify the presence of quantumness via an average over all physically relevant modal decompositions. We investigate extremal states for such a measure: SU(2)-coherent states possess the least quantumness whereas the opposite extreme is inhabited by states with maximally spread Majorana constellations.

Topological Insulators Quantum Mechanics. (arXiv:2110.11455v1 [hep-th])

上午10:17 | | | J. Gamboa, F. Mendez | | | quant-ph updates on arXiv.org |

Topological insulators in three dimensions are studied as a problem of supersymmetric quantum mechanics. The spin-orbit coupling is induced as a consequence of the supersymmetrization procedure and we show that it is equivalent to the appearance of a $SU(2)$ connection. The procedure presented in this letter is general and valid for any three-dimensional quantum system. The approach allows — in principle — to study a wide range of topological insulators as standard quantum mechanical problems. As an illustration the three-dimensional harmonic oscillator and the Aharonov-Bohm effect are studied in detail.

The Cosmic Void. (arXiv:2110.11859v1 [physics.hist-ph])

上午10:17 | | | physics.hist-ph updates on arXiv.org |

Authors: Eddy Keming Chen

What exists at the fundamental level of reality? On the standard picture, the fundamental reality contains (among other things) fundamental matter, such as particles, fields, or even the quantum state. Non-fundamental facts are explained by facts about fundamental matter, at least in part. In this paper, I introduce a non-standard picture called the “cosmic void” in which the universe is devoid of any fundamental material ontology. Facts about tables and chairs are recovered from a special kind of laws that satisfy strong determinism. All non-fundamental facts are completely explained by nomic facts. I discuss a concrete example of this picture in a strongly deterministic version of the many-worlds theory of quantum mechanics. I discuss some philosophical and scientific challenges to this view, as well as some connections to ontological nihilism.

Interdimensionality. (arXiv:2110.11394v1 [physics.gen-ph])

上午10:17 | | | gr-qc updates on arXiv.org |

Authors: Karl Svozil

In this speculative analysis, interdimensionality is introduced as the (co)existence of universes embedded into larger ones. These interdimensional universes may be isolated or intertwined, suggesting a variety of interdimensional intrinsic phenomena that can only be understood in terms of the outer, extrinsic reality.

上午10:17 | | | gr-qc updates on arXiv.org |

Authors: S. Nesseris, D. Sapone, M. Martinelli, D. Camarena, V. Marra, Z. Sakr, J. Garcia-Bellido, C.J.A.P. Martins, C. Clarkson, A. Da Silva, P. Fleury, L. Lombriser, J.P. Mimoso, S. Casas, V. Pettorino, I. Tutusaus, A. Amara, N. Auricchio, C. Bodendorf, D. Bonino, E. Branchini, M. Brescia, V. Capobianco, C. Carbone, J. Carretero, M. Castellano, S. Cavuoti, A. Cimatti, R. Cledassou, G. Congedo, L. Conversi, Y. Copin, L. Corcione, F. Courbin, M. Cropper, H. Degaudenzi, M. Douspis, F. Dubath, C.A.J. Duncan, X. Dupac, S. Dusini, A. Ealet, S. Farrens, P. Fosalba, M. Frailis, E. Franceschi, M. Fumana, B. Garilli, B. Gillis, C. Giocoli, A. Grazian, F. Grupp, S.V.H. Haugan, W. Holmes, F. Hormuth, K. Jahnke, S. Kermiche, A. Kiessling, T. Kitching, M. Kümmel, M. Kunz, H. Kurki-Suonio, S. Ligori, P.B. Lilje, et al. (51 additional authors not shown)

The standard cosmological model is based on the simplifying assumptions of a spatially homogeneous and isotropic universe on large scales. An observational detection of their violation, at any redshift, would immediately indicate the breakdown of the aforementioned assumptions or presence of new physics. We quantify the ability of the Euclid mission, together with contemporary surveys, to improve the current sensitivity of null tests of the canonical cosmological constant and cold dark matter (LCDM) model, in the redshift range $0<z<1.8$. We consider both currently available data and simulated Euclid and external data products based on a LCDM fiducial model, an evolving dark energy model assuming the Chevallier-Polarski-Linder (CPL) parametrization or an inhomogeneous Lema\^{\i}tre-Tolman-Bondi model with a cosmological constant (LLTB), and carry out two separate, albeit complementary, analyses: a machine learning reconstruction based on genetic algorithms and a theory-agnostic parametric approach based on polynomial reconstruction and binning of the data, in order not to make assumptions about any particular model. We find that using the machine learning approach Euclid can (in combination with external probes) improve current constraints on null tests of the LCDM by approximately a factor of two to three, while in the case of the binning approach, Euclid can provide tighter constraints than the genetic algorithms by a further factor of two in the case of the LCDM mock, albeit in certain cases may be biased against or missing some features of models far from LCDM, as is the case with the CPL and LLTB mocks. Our analysis highlights the importance of synergies between Euclid and other surveys, which are crucial to provide tighter constraints over an extended redshift range, for a plethora of different consistency tests of some of the main assumptions of the current cosmological paradigm.

Idealizations and analogies: Explaining critical phenomena

2021年10月24日 星期日 下午3:43 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Rodriguez, Quentin (2021) Idealizations and analogies: Explaining critical phenomena. Studies in History and Philosophy of Science Part A, 89. pp. 235-247. ISSN 00393681

The Quantum Revolution in Philosophy (Book Review)

2021年10月24日 星期日 下午3:42 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Chen, Eddy Keming (2020) The Quantum Revolution in Philosophy (Book Review). The Philosophical Review, 129 (2). pp. 302-308.

Time’s Arrow and Self-Locating Probability

2021年10月24日 星期日 下午3:41 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Chen, Eddy Keming (2021) Time’s Arrow and Self-Locating Probability. Philosophy and Phenomenological Research.

How to Choose a Gauge? The case of Hamiltonian Electromagnetism

2021年10月24日 星期日 下午3:40 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gomes, Henrique and Butterfield, Jeremy (2021) How to Choose a Gauge? The case of Hamiltonian Electromagnetism. [Preprint]

Isolated systems and their symmetries, part II: local and global symmetries of field theories

2021年10月24日 星期日 下午3:39 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Wallace, David (2021) Isolated systems and their symmetries, part II: local and global symmetries of field theories. [Preprint]

Isolated Systems and their Symmetries, Part I: General Framework and Particle-Mechanics Examples

2021年10月24日 星期日 下午3:39 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Wallace, David (2021) Isolated Systems and their Symmetries, Part I: General Framework and Particle-Mechanics Examples. [Preprint]

Quasi-set theory for a quantum ontology of properties

2021年10月24日 星期日 下午3:38 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Holik, Federico and Jorge, Juan Pablo and Krause, Décio and Lombardi, Olimpia (2021) Quasi-set theory for a quantum ontology of properties. [Preprint]

Our Fundamental Physical Space: An Essay on the Metaphysics of the Wave Function

2021年10月24日 星期日 上午5:59 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Chen, Eddy Keming (2017) Our Fundamental Physical Space: An Essay on the Metaphysics of the Wave Function. The Journal of Philosophy, 114 (7). pp. 333-365. ISSN 0022-362X

Quantum Mechanics Without Indeterminacy

2021年10月22日 星期五 下午4:25 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Glick, David (2021) Quantum Mechanics Without Indeterminacy. [Preprint]

Weak-Measurement-Induced Asymmetric Dephasing: Manifestation of Intrinsic Measurement Chirality

2021年10月18日 星期一 下午6:00 | | | Kyrylo Snizhko, Parveen Kumar, Nihal Rao, and Yuval Gefen | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Kyrylo Snizhko, Parveen Kumar, Nihal Rao, and Yuval Gefen

Geometrical dephasing is distinct from dynamical dephasing in that it depends on the trajectory traversed, hence it reverses its sign upon flipping the direction in which the path is traced. Here we study sequences of generalized (weak) measurements that steer a system in a closed trajectory. The re…

[Phys. Rev. Lett. 127, 170401] Published Mon Oct 18, 2021

]]>2021年10月16日 星期六 上午11:02 | | | Roman Stricker, Davide Vodola, Alexander Erhard, Lukas Postler, Michael Meth, Martin Ringbauer, Philipp Schindler, Rainer Blatt, Markus Müller, Thomas Monz | | | quant-ph updates on arXiv.org |

In quantum information processing quantum operations are often processed alongside measurements which result in classical data. Due to the information gain of classical measurement outputs non-unitary dynamical processes can take place on the system, for which common quantum channel descriptions fail to describe the time evolution. Quantum measurements are correctly treated by means of so-called quantum instruments capturing both classical outputs and post-measurement quantum states. Here we present a general recipe to characterize quantum instruments alongside its experimental implementation and analysis. Thereby, the full dynamics of a quantum instrument can be captured, exhibiting details of the quantum dynamics that would be overlooked with common tomography techniques. For illustration, we apply our characterization technique to a quantum instrument used for the detection of qubit loss and leakage, which was recently implemented as a building block in a quantum error correction (QEC) experiment (Nature 585, 207-210 (2020)). Our analysis reveals unexpected and in-depth information about the failure modes of the implementation of the quantum instrument. We then numerically study the implications of these experimental failure modes on QEC performance, when the instrument is employed as a building block in QEC protocols on a logical qubit. Our results highlight the importance of careful characterization and modelling of failure modes in quantum instruments, as compared to simplistic hardware-agnostic phenomenological noise models, which fail to predict the undesired behavior of faulty quantum instruments. The presented methods and results are directly applicable to generic quantum instruments.

Coherent energy fluctuation theorems: theory and experiment. (arXiv:2110.07061v1 [quant-ph])

2021年10月16日 星期六 上午11:02 | | | K. Khan, J. Sales Araújo, W. F. Magalhães, G. H. Aguilar, B. de Lima Bernardo | | | quant-ph updates on arXiv.org |

Heat, work and entropy production: the statistical distribution of such quantities are constrained by the fluctuation theorems (FT), which reveal crucial properties about the nature of non-equilibrium dynamics. In this paper we report theoretical and experimental results regarding two FT for a new quantity, named coherent energy, which is an energy form directly associated with the coherences of the quantum state. We also demonstrate that this quantity behaves as a thermodynamic arrow of time for unitary evolutions, that is, in the absence of entropy production. The experiment is implemented in an all-optical setup in which the system is encoded in the polarization of one photon of a pair. The FT are demonstrated using the two-point measurement protocol, executed using the other photon of the pair, allowing to assess the probability distributions directly from the outcomes of the experiment.

2021年10月16日 星期六 上午11:02 | | | Stefano Gogioso | | | quant-ph updates on arXiv.org |

We use purity, a principle borrowed from the foundations of quantum information, to show that all special symmetric $\dagger$-Frobenius algebras in $\operatorname{CPM}\left(\operatorname{fHilb}\right)$ — and, in particular, all classical structures — are canonical, i.e. that they arise by doubling of special symmetric $\dagger$-Frobenius algebras in $\operatorname{fHilb}$. This provides an exact classification of finite-dimensional quantum observables.

Physical mechanisms underpinning the vacuum permittivity. (arXiv:2110.07223v1 [quant-ph])

2021年10月16日 星期六 上午11:02 | | | Gerd Leuchs, Margaret Hawton, Luis L. Sanchez-Soto | | | quant-ph updates on arXiv.org |

Debate about the emptiness of the space goes back to the prehistory of science and is epitomized by the Aristotelian \emph{horror vacui}, which can be seen as the precursor of the ether, whose modern version is the dynamical quantum vacuum. Here, we change our view to \emph{gaudium vacui} and discuss how the vacuum fluctuations fix the value of the permittivity $\varepsilon_{0}$ and permeability $\mu_{0}$.

2021年10月16日 星期六 上午11:02 | | | E. Alex Wollack, Agnetta Y. Cleland, Rachel G. Gruenke, Zhaoyou Wang, Patricio Arrangoiz-Arriola, Amir H. Safavi-Naeini | | | quant-ph updates on arXiv.org |

Precisely engineered mechanical oscillators keep time, filter signals, and sense motion, making them an indispensable part of today’s technological landscape. These unique capabilities motivate bringing mechanical devices into the quantum domain by interfacing them with engineered quantum circuits. Proposals to combine microwave-frequency mechanical resonators with superconducting devices suggest the possibility of powerful quantum acoustic processors. Meanwhile, experiments in several mechanical systems have demonstrated quantum state control and readout, phonon number resolution, and phonon-mediated qubit-qubit interactions. Currently, these acoustic platforms lack processors capable of controlling multiple mechanical oscillators’ quantum states with a single qubit, and the rapid quantum non-demolition measurements of mechanical states needed for error correction. Here we use a superconducting qubit to control and read out the quantum state of a pair of nanomechanical resonators. Our device is capable of fast qubit-mechanics swap operations, which we use to deterministically manipulate the mechanical states. By placing the qubit into the strong dispersive regime with both mechanical resonators simultaneously, we determine the resonators’ phonon number distributions via Ramsey measurements. Finally, we present quantum tomography of the prepared nonclassical and entangled mechanical states. Our result represents a concrete step toward feedback-based operation of a quantum acoustic processor.

Why and whence the Hilbert space in quantum theory?. (arXiv:2110.05932v2 [physics.gen-ph] UPDATED)

2021年10月16日 星期六 上午11:02 | | | Yu. V. Brezhnev | | | quant-ph updates on arXiv.org |

We explain why and how the Hilbert space comes about in quantum theory. The axiomatic structures of a vector space, of scalar product, of orthogonality, and of the linear functional are derivable from the statistical description of quantum micro-events and from Hilbertian sum of squares $|\mathfrak{a}_1|^2+|\mathfrak{a}_2|^2+\cdots$. The latter leads (non-axiomatically) to the standard writing of the Born formula $\mathtt{f}=|\langle\psi|\varphi\rangle|^2$. As a corollary, the status of Pythagorean theorem, the concept of a length, and the 6-th Hilbert problem undergo a quantum `revision’. An issue of deriving the normed topology is likely solvable in the affirmative and has been stated as a mathematical problem.

2021年10月16日 星期六 上午11:02 | | | physics.hist-ph updates on arXiv.org |

Authors: Badis Ydri

In this essay a quantum-dualistic, perspectival and synchronistic interpretation of quantum mechanics is further developed in which the classical world-from-decoherence which is perceived (decoherence) and the perceived world-in-consciousness which is classical (collapse) are not necessarily identified. Thus, Quantum Reality or “{\it unus mundus}” is seen as both i) a physical non-perspectival causal Reality where the quantum-to-classical transition is operated by decoherence, and as ii) a quantum linear superposition of all classical psycho-physical perspectival Realities which are governed by synchronicity as well as causality (corresponding to classical first-person observes who actually populate the world). This interpretation is termed the Nietzsche-Jung-Pauli interpretation and is a re-imagining of the Wigner-von Neumann interpretation which is also consistent with some reading of Bohr’s quantum philosophy.

2021年10月16日 星期六 上午11:02 | | | physics.hist-ph updates on arXiv.org |

Authors: W.M. Stuckey, Timothy McDevitt, Michael Silberstein

We review how the kinematic structures of special relativity and quantum mechanics both stem from the relativity principle, i.e., “no preferred reference frame” (NPRF). Essentially, NPRF applied to the measurement of the speed of light $c$ gives the light postulate and leads to the geometry of Minkowski spacetime, while NPRF applied to the measurement of Planck’s constant $h$ gives “average-only” projection and leads to the denumerable-dimensional Hilbert space of quantum mechanics. These kinematic structures contain the counterintuitive aspects (“mysteries”) of time dilation, length contraction, and quantum entanglement. In this essay, we extend the application of NPRF to the gravitational constant $G$ and show that it leads to the “mystery” of the contextuality of mass in general relativity. Thus, we see an underlying coherence and integrity in modern physics via its “mysteries” and the fundamental constants $c$, $h$, and $G$.

2021年10月16日 星期六 上午11:02 | | | physics.hist-ph updates on arXiv.org |

Authors: Henrique Gomes

The following questions are germane to our understanding of gauge-(in)variant quantities and physical possibility: in which ways are gauge transformations and spacetime diffeomorphisms similar, and in which are they different? To what extent are we justified in endorsing different attitudes — sophistication, quidditism/haecceitism, or full elimination — towards each? In a companion paper, I assess new and old contrasts between the two types of symmetries. In this one, I propose a new contrast: whether the symmetry changes pointwise the dynamical properties of a given field. This contrast distinguishes states that are related by a gauge-symmetry from states related by generic spacetime diffeomorphisms, as being `pointwise dynamically indiscernible’. Only the rigid isometries of homogeneous spacetimes fall in the same category, but they are neither local nor modally robust, in the way that gauge transformations are. In spite of this difference, I argue that for both gauge transformations and spacetime diffeomorphisms, symmetry-related models are best understood through the doctrine of `sophistication’.

2021年10月16日 星期六 上午11:02 | | | physics.hist-ph updates on arXiv.org |

Authors: Henrique Gomes

How should we understand gauge-(in)variant quantities and physical possibility? Does the redundancy present in gauge theory pose different interpretational issues than those present in general relativity? Here, I will assess new and old contrasts between general relativity and Yang-Mills theory, in particular, in relation to their symmetries. I will focus these comparisons on four topics: (i) non-locality, (ii) conserved charges, (iii) Aharonov-Bohm effect, and (iv) the choice of representational conventions of the field configuration. In a companion paper, I propose a new contrast and defend sophistication for both theories.

2021年10月16日 星期六 上午11:02 | | | physics.hist-ph updates on arXiv.org |

Authors: Henrique Gomes

A fundamental tenet of gauge theory is that physical quantities should be gauge-invariant. This prompts the question: can gauge symmetries have physical significance? On one hand, the Noether theorems relate conserved charges to symmetries, endowing the latter with physical significance, though this significance is sometimes taken as indirect. But for theories in spatially finite and bounded regions, the standard Noether charges are not gauge-invariant. I here argue that gauge-\emph{variance} of charges is tied to the nature of the non-locality within gauge theories. I will flesh out these links by providing a chain of (local) implications: `local conservation laws’${\Rightarrow}$ `conserved regional charges’ $\Leftrightarrow$ `non-separability’ ${\Leftrightarrow}$ `direct empirical significance of symmetries’.

An Algebraic Approach to Physical Fields. (arXiv:2108.07184v2 [physics.hist-ph] UPDATED)

2021年10月16日 星期六 上午11:02 | | | physics.hist-ph updates on arXiv.org |

Authors: Lu Chen, Tobias Fritz

According to the algebraic approach to spacetime, a thoroughgoing dynamicism, physical fields exist without an underlying manifold. This view is usually implemented by postulating an algebraic structure (e.g., commutative ring) of scalar-valued functions, which can be interpreted as representing a scalar field, and deriving other structures from it. In this work, we point out that this leads to the unjustified primacy of an undetermined scalar field. Instead, we propose to consider algebraic structures in which all (and only) physical fields are primitive. We explain how the theory of \emph{natural operations} in differential geometry — the modern formalism behind classifying diffeomorphism-invariant constructions — can be used to obtain concrete implementations of this idea for any given collection of fields.

For concrete examples, we illustrate how our approach applies to a number of particular physical fields, including electrodynamics coupled to a Weyl spinor.

Lessons from the information paradox

2021年10月16日 星期六 上午11:02 | | | ScienceDirect Publication: Physics ReportsScienceDirect RSShttps://www.sciencedirect.com/journal/physics-reportsRSS for NodeTue, 23 Jul 2019 10:02:48 GMTCopyright © 2019 Elsevier B.V. All rights reservedRapid solidification as non-ergodic phenomenonPublication date: 20 July 2019Source: Physics Reports, Volume 818Author(s): P.K. Galenko, D. JouAbstractRapid solidification is a relevant physical phenomenon in material sciences, whose theoretical analysis requires going beyond the limits of local equilibrium statistical physics and thermodynamics and, in particular, taking account of ergodicity breaking and of generalized formulation of thermodynamics. The ergodicity breaking is related to the time symmetry breaking and to the presence of some kinds of fluxes and gradient flows making that an average of microscopic variables along time is different than an average over some chosen statistical ensemble. In fast processes, this is due, for instance, to the fact that the system has no time enough to explore the who |

Publication date: Available online 12 October 2021

**Source:** Physics Reports

Author(s): Suvrat Raju

Light, delayed: The Shapiro Effect and the Newtonian Limit. (arXiv:2110.07016v1 [gr-qc])

2021年10月16日 星期六 上午11:02 | | | gr-qc updates on arXiv.org |

Authors: Markus Pössel

The Shapiro effect, also known as the gravitational time delay, is close kin to the gravitational deflection of light that was the central topic of our Summer School. It is also an interesting test bed for exploring a topic that provides the foundations for most of the calculations we have done in this school, yet is highly complex when treated more rigorously: the question of the Newtonian limit, and of the post-Newtonian corrections that must be applied to include the leading-order effects of general relativity. This contribution discusses simplified derivations for the gravitational redshift and the Shapiro effect, as well as astrophysical situations in which the Shapiro effect can be measured.

2021年10月16日 星期六 上午11:02 | | | gr-qc updates on arXiv.org |

Authors: Sylvain Carrozza, Philipp A. Hoehn

We introduce a general framework realizing edge modes in (classical) gauge field theory as dynamical reference frames, an often suggested interpretation that we make entirely explicit. We focus on a bounded region $M$ with a co-dimension one time-like boundary $\Gamma$, which we embed in a global spacetime. Taking as input a variational principle at the global level, we develop a systematic formalism inducing consistent variational principles (and in particular, boundary actions) for the subregion $M$. This relies on a post-selection procedure on $\Gamma$, which isolates the subsector of the global theory compatible with a general choice of gauge-invariant boundary conditions for the dynamics in $M$. Crucially, the latter relate the configuration fields on $\Gamma$ to a dynamical frame field carrying information about the spacetime complement of $M$; as such, they may be equivalently interpreted as frame-dressed or relational observables. Generically, the external frame field keeps an imprint on the ensuing dynamics for subregion $M$, where it materializes itself as a local field on the time-like boundary $\Gamma$; in other words, an edge mode. We identify boundary symmetries as frame reorientations and show that they divide into three types, depending on the boundary conditions, that affect the physical status of the edge modes. Our construction relies on the covariant phase space formalism, and is in principle applicable to any gauge (field) theory. We illustrate it on three standard examples: Maxwell, Abelian Chern-Simons and non-Abelian Yang-Mills theories. In complement, we also analyze a mechanical toy-model to connect our work with recent efforts on (quantum) reference frames.

2021年10月14日 星期四 下午1:25 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

French, Steven (2021) Fundamentality. [Preprint]

2021年10月14日 星期四 下午1:22 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Merritt, David (2020) Cosmological Realism. [Preprint]

Neither Contextuality nor Nonlocality Admits Catalysts

2021年10月13日 星期三 下午6:00 | | | Martti Karvonen | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Martti Karvonen

We show that the resource theory of contextuality does not admit catalysts, i.e., there are no correlations that can enable an otherwise impossible resource conversion and still be recovered afterward. As a corollary, we observe that the same holds for nonlocality. As entanglement allows for catalys…

[Phys. Rev. Lett. 127, 160402] Published Wed Oct 13, 2021

Anderson Localization of Composite Particles

2021年10月12日 星期二 下午6:00 | | | Fumika Suzuki, Mikhail Lemeshko, Wojciech H. Zurek, and Roman V. Krems | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Fumika Suzuki, Mikhail Lemeshko, Wojciech H. Zurek, and Roman V. Krems

We investigate the effect of coupling between translational and internal degrees of freedom of composite quantum particles on their localization in a random potential. We show that entanglement between the two degrees of freedom weakens localization due to the upper bound imposed on the inverse part…

[Phys. Rev. Lett. 127, 160602] Published Tue Oct 12, 2021

2021年10月11日 星期一 下午6:00 | | | Kohei Yoshimura and Sosuke Ito | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Kohei Yoshimura and Sosuke Ito

The thermodynamic uncertainty relation and speed limit provide fundamental bounds relating basic properties of chemical reaction networks and their diffusion coefficients.

[Phys. Rev. Lett. 127, 160601] Published Mon Oct 11, 2021

On the alleged extra-structures of quantum mechanics

2021年10月11日 星期一 下午3:45 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Romano, Davide (2021) On the alleged extra-structures of quantum mechanics. [Preprint]

]]>下午12:15 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Di Biagio, Andrea and Rovelli, Carlo (2021) Relational Quantum Mechanics is about Facts, not States: A reply to Pienaar and Brukner. [Preprint]

Trans-Planckian Philosophy of Cosmology

下午12:10 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Schneider, Mike D. (2021) Trans-Planckian Philosophy of Cosmology. [Preprint]

Mutually Unbiased Quantum Observables. (arXiv:2110.03099v1 [quant-ph])

上午9:44 | | | Stan Gudder | | | quant-ph updates on arXiv.org |

We begin by defining mutually unbiased (MU) observables on a finite dimensional Hilbert space. We also consider the more general concept of parts of MU observables. The relationships between MU observables, value-complementary observables and two other conditions involving sequential products of observables are discussed. We next present a special motivating case of MU observables called finite position and momentum observables. These are atomic observables related by a finite Fourier transform. Finite position and momentum observables are employed to give examples of parts of MU observables that are value-complementary and those that are not value-complementary. Various open problems involving these concepts are presented. These problems mainly involve extending this work from sharp observables to unsharp observables.

上午9:44 | | | Masanao Ozawa | | | quant-ph updates on arXiv.org |

In this paper, we present a general theory of finite quantum measurements, for which we assume that the state space of the measured system is a finite dimensional Hilbert space and that the possible outcomes of a measurement is a finite set of the real numbers. We develop the theory in a deductive manner from the basic postulates for quantum mechanics and a few plausible axioms for general quantum measurements. We derive an axiomatic characterization of all the physically realizable finite quantum measurements. Mathematical tools necessary to describe measurement statistics, such as POVMs and quantum instruments, are not assumed at the outset, but we introduce them as natural consequences of our axioms. Our objective is to show that those mathematical tools can be naturally derived from obvious theoretical requirements.

From Classical to quantum stochastic process. (arXiv:2110.03668v1 [cond-mat.stat-mech])

上午9:44 | | | Gustavo Montes, Soham Biswas, Thomas Gorin | | | quant-ph updates on arXiv.org |

We construct quantum analogs of classical stochastic processes, by replacing random “which path” decisions with superposition of all paths. This procedure typically leads to non-unitary quantum evolution, where coherences are continuously generated and destroyed. In spite of their transient nature, these coherences can change the scaling behavior of classical observables. Using the zero temperature Glauber dynamics in a linear Ising spin chain, we find quantum analogs with different domain growth exponents. In some cases, this exponent is even smaller than for the original classical process, which means that coherence can lead to an important speed up the relaxation process.

上午9:44 | | | Eiji Konishi | | | quant-ph updates on arXiv.org |

We derive the projection hypothesis in projective quantum measurement by restricting the set of observables. This projection hypothesis accompanies a bipartite system with the von Neumann-type interaction, which consists of a quantum mechanical system, with a meter variable to be measured, and a quantum field theoretically macroscopic extended object, that is, a spatiotemporally inhomogeneous Bose-Einstein condensate in quantum field theory with the quantum coordinate, that is, the zero-energy Goldstone mode(s) of the spontaneously broken global spatial translational symmetry. The key steps in the derivation are the return of the symmetry translation of this quantum coordinate to the inverse translation of the c-number spatial coordinate in quantum field theory and the reduction of quantum fluctuations to classical fluctuations with respect to the Goldstone mode(s) due to a superselection rule.

上午9:44 | | | Justin K. Perron, Charles DeLeone, Shahed Sharif, Tom Carter, Joshua M. Grossman, Gina Passante, Joshua Sack | | | quant-ph updates on arXiv.org |

Currently, education and workforce training in quantum information science and technology (QIST) exists primarily at the graduate and postdoctoral levels, with few undergraduate efforts beginning to grow out of these. In order to meet the anticipated quantum workforce needs and to ensure that the workforce is demographically representative and inclusive to all communities, the United States must expand these efforts at the undergraduate level beyond what is occurring at larger PhD granting institutions and incorporate quantum information science into the curriculum at the nation’s predominantly undergraduate institutions (PUIs). On June 3rd and 4th, 2021 the Quantum Undergraduate Education and Scientific Training (QUEST) workshop was held virtually with the goal of bringing together faculty from PUIs to learn the state of undergraduate QIST education, identify challenges associated with implementing QIST curriculum at PUIs, and to develop strategies and solutions to deal with these challenges. This manuscript summarizes the results of workshop discussions with the hope of assisting faculty at PUIs attempting to incorporate quantum information science into their curriculum.

上午9:44 | | | Francesco Coradeschi, Antonia Micol Frassino, Thiago Guerreiro, Jennifer Rittenhouse West, Enrico Junior Schioppa | | | quant-ph updates on arXiv.org |

A theoretical framework for the quantization of gravity has been an elusive Holy Grail since the birth of quantum theory and general relativity. While generations of scientists have attempted solutions to this deep riddle, an alternative path built upon the idea that experimental evidence could determine whether gravity is quantized has been decades in the making. The possibility of an experimental answer to the question of the quantization of gravity is of renewed interest in the era of gravitational wave detectors. We review and investigate an important subset of phenomenological quantum gravity, detecting quantum signatures of weak gravitational fields in table-top experiments and interferometers.

The Life and Science of Thanu Padmanabhan. (arXiv:2110.03208v1 [physics.hist-ph])

上午9:44 | | | physics.hist-ph updates on arXiv.org |

Authors: Jasjeet Singh Bagla, Krishnakanta Bhattacharya, Sumanta Chakraborty, Sunu Engineer, Valerio Faraoni, Sanved Kolekar, Dawood Kothawala, Kinjalk Lochan, Sujoy Modak, V. Parameswaran Nair, Aseem Paranjape, Krishnamohan Parattu, Sarada G. Rajeev, Bibhas Ranjan Majhi, Tirthankar Roy Choudhury, Mohammad Sami, Sudipta Sarkar, Sandipan Sengupta, T. R. Seshadri, S. Shankaranarayanan, Suprit Singh, Tejinder P. Singh, L. Sriramkumar, Urjit Yajnik

Thanu Padmanabhan was a renowned Indian theoretical physicist known for his research in general relativity, cosmology, and quantum gravity. In an extraordinary career spanning forty-two years, he published more than three hundred research articles, wrote ten highly successful technical and popular books, and mentored nearly thirty graduate students and post-doctoral fellows. He is best known for his deep work investigating gravitation as an emergent thermodynamic phenomenon. He was an outstanding teacher, and an indefatigable populariser of science, who travelled very widely to motivate and inspire young students. Paddy, as he was affectionately known, was also a close friend to his students and collaborators, treating them as part of his extended academic family. On September 17, 2021 Paddy passed away very unexpectedly, at the age of sixty-four and at the height of his research career, while serving as a Distinguished Professor at the Inter-University Centre for Astronomy and Astrophysics, Pune. His untimely demise has come as a shock to his family and friends and colleagues. In this article, several of them have come together to pay their tributes and share their fond memories of Paddy.

Probability distribution for the quantum universe. (arXiv:2110.03050v1 [hep-th])

上午9:43 | | | gr-qc updates on arXiv.org |

Authors: Alex Kehagias, Hervé Partouche, Nicolaos Toumbas

We determine the inner product on the Hilbert space of wavefunctions of the universe by imposing the Hermiticity of the quantum Hamiltonian in the context of the minisuperspace model. The corresponding quantum probability density reproduces successfully the classical probability distribution in the $\hbar \to 0$ limit, for closed universes filled with a perfect fluid of index $w$. When $-1/3<w\le 1$, the wavefunction is normalizable and the quantum probability density becomes vanishingly small at the big bang/big crunch singularities, at least at the semi-classical level. Quantum expectation values of physical geometrical quantities, which diverge classically at the singularities, are shown to be finite.

上午9:43 | | | gr-qc updates on arXiv.org |

Authors: Gabriel Leuenberger

The causal set program as well as the Wolfram physics project leave open the problem of how a graph that is a (3+1)-dimensional Minkowski-spacetime according to its simple geodesic distances, could be generated solely from simple deterministic rules. This paper provides a solution by describing simple rules that characterize discrete Lorentz boosts between 4D lattice graphs, which combine further to form Wigner rotations that produce isotropy and lead to the emergence of the continuous Lorentz group and the (3+1)-dimensional Minkowski-spacetime. On such graphs, the speed of light, the proper time interval, as well as the proper length are all shown to be highly accurate.

上午9:43 | | | gr-qc updates on arXiv.org |

Authors: George Alestas, Ioannis Antoniou, Leandros Perivolaropoulos

We use an up to date compilation of Tully-Fisher data to search for transitions in the evolution of the Tully-Fisher relation. Using an up to date data compilation, we find hints at $\approx 3\sigma$ level for a transition at critical distances $D_c \simeq 9 Mpc$ and $D_c \simeq 17 Mpc$. We split the full sample in two subsamples according to the measured galaxy distance with respect to a splitting distance $D_c$ and identify the likelihood of the best fit slope and intercept of one sample with respect to the best fit corresponding values of the other sample. For $D_c \simeq 9 Mpc$ and $D_c \simeq 17 Mpc$ we find a tension between the two subsamples at a level of $\Delta \chi^2 > 17\; (3.5\sigma)$. Using a Monte-Carlo simulation we demonstrate that this result is robust with respect to random statistical and systematic variations of the galactic distances. If the tension is interpreted as due to a gravitational strength transition, it would imply a shift of the effective gravitational constant to lower values for distances larger than $D_c$ by $\frac{\Delta G}{G}\simeq -0.1$. Such a shift is of the anticipated sign and magnitude but at somewhat lower distance (redshift) than the gravitational transition recently proposed to address the Hubble and growth tensions ($\frac{\Delta G}{G}\simeq -0.1$ at transition redshift $z_t\lesssim 0.01$ ($D_c\lesssim 40 Mpc$)).

Carroll symmetry, dark energy and inflation. (arXiv:2110.02319v1 [hep-th] CROSS LISTED)

上午9:43 | | | gr-qc updates on arXiv.org |

Authors: Jan de Boer, Jelle Hartong, Niels A. Obers, Watse Sybesma, Stefan Vandoren

Carroll symmetry arises from Poincar\’e symmetry upon taking the limit of vanishing speed of light. We determine the constraints on the energy-momentum tensor implied by Carroll symmetry and show that for energy-momentum tensors of perfect fluid form, these imply an equation of state ${\cal E}+P=0$ for energy density plus pressure. Therefore Carroll symmetry might be relevant for dark energy and inflation. In the Carroll limit, the Hubble radius goes to zero and outside it recessional velocities are naturally large compared to the speed of light. The de Sitter group of isometries, after the limit, becomes the conformal group in Euclidean flat space. We also study the Carroll limit of chaotic inflation, and show that the scalar field is naturally driven to have an equation of state with $w=-1$. Finally we show that the freeze-out of scalar perturbations in the two point function at horizon crossing is a consequence of Carroll symmetry.

To make the paper self-contained, we include a brief pedagogical review of Carroll symmetry, Carroll particles and Carroll field theories that contains some new material as well. In particular we show, using an expansion around speed of light going to zero, that for scalar and Maxwell type theories one can take two different Carroll limits at the level of the action. In the Maxwell case these correspond to the electric and magnetic limit. For point particles we show that there are two types of Carroll particles: those that cannot move in space and particles that cannot stand still.

Analyzing Nonequilibrium Quantum States through Snapshots with Artificial Neural Networks

2021年10月7日 星期四 下午6:00 | | | A. Bohrdt, S. Kim, A. Lukin, M. Rispoli, R. Schittko, M. Knap, M. Greiner, and J. Léonard | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): A. Bohrdt, S. Kim, A. Lukin, M. Rispoli, R. Schittko, M. Knap, M. Greiner, and J. Léonard

Current quantum simulation experiments are starting to explore nonequilibrium many-body dynamics in previously inaccessible regimes in terms of system sizes and timescales. Therefore, the question emerges as to which observables are best suited to study the dynamics in such quantum many-body systems…

[Phys. Rev. Lett. 127, 150504] Published Thu Oct 07, 2021

The statistical interpretation: Born, Heisenberg and von Neumann, 1926-27

2021年10月7日 星期四 上午12:28 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Bacciagaluppi, Guido (2021) The statistical interpretation: Born, Heisenberg and von Neumann, 1926-27. [Preprint]

The Double Nature of Maxwell’s Physical Analogies

2021年10月7日 星期四 上午12:21 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Nappo, Francesco (2021) The Double Nature of Maxwell’s Physical Analogies. [Preprint]

2021年10月6日 星期三 上午8:00 | | | Leonardo Benini | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 06 October 2021; doi:10.1038/s41567-021-01389-8

The duality of a multitude

]]>Planck’s constant and the gravitational constant embody natural units of length, mass, and time. When we replace the universal constants with natural Planck units, a hidden structure appears in the equations of physics comprising ratios of length, mass, and time to the Planck scale. It is the proportions of Planck units that define observable physical phenomena and not the composite values of the constants. Natural unit formulas offer more granular information about the structure of matter and radiation than equations written with hbar and G. These natural formulas reveal physical relationships explaining the correspondence between classical and quantum phenomena. Relationships between rest mass, velocity, and wavelength show how classical and quantum mechanical momentum and energy are related, suggesting that momentum is universally a function of wavelength and not velocity.

]]>The mind-body problem is reviewed in the context of a non-technical account of quantum theory. The importance of clearly defining: `what is physical?’ is highlighted, since only then can we give meaning to the concept `non-physical’. Physicality is defined in terms of interaction, which is in turn defined to be a correlated exchange of information. This is asserted to be the basis of any meaningful concept of epistemology. Hence, it is argued that a non-physical entity can not `know’ anything about the world. Information transfer is then discussed in terms of quantum entanglement and an argument for our perception of time is presented. It is then contended that the notion of `mind’ may be meaningfully discussed in the context of a quantum theoretic framework.

]]>In a recent series of papers and lectures, John Conway and Simon Kochen presented The Free Will Theorem. “It asserts, roughly, that if indeed we humans have free will, then elementary particles already have their own small share of this valuable commodity.” Perhaps the primary motivation of their papers was to place stringent constraints on quantum mechanical hidden variable theories, which they indeed do. Nevertheless, the notion of free will is crucial to the proof and they even speculate that the free will afforded to elementary particles is the ultimate explanation of our own free will. I don’t challenge the mathematics/logic of their proof but rather their premises. Free will and determinism are, for me, not nearly adequately clarified for them to form the bases of a theoretical proof. In addition, they take for granted supplemental concepts in quantum mechanics that are in need of further explanation. It’s also not clear to me what utility is afforded by the free will theorem, i.e., what, if anything, follows from it. Despite the cheeky subtitle of my essay, I do think that the explicit introduction of free will into discussions of hidden variables and other interpretations of quantum mechanics might help expose foibles in many of those deliberations. For this reason, I consider the Conway-Kochen free will theorem to be a positive contribution to the philosophy of quantum mechanics.

]]>Gravity-related collapse of the wave function and spontaneous heating: revisiting the experimental bounds. (arXiv:2109.14980v1 [quant-ph])

上午9:47 | | | Andrea Vinante, Hendrik Ulbricht | | | quant-ph updates on arXiv.org |

The possibility that the collapse of the wave function in quantum mechanics is a real and ultimately connected to (classical) gravity has been debated for decades, with main contributions by Di\’osi and Penrose. In particular, Di\’osi proposed a noise-based dynamical reduction model, which captures the same orders of magnitude for the collapse time suggested by Penrose based on heuristic arguments. This is known in literature as the DP model (Di\’osi-Penrose). A peculiarity of the DP model is the prediction of spontaneous heating of matter, which can be tested without the need for massive quantum superpositions. Notably, a very similar effect is predicted by recent theoretical approaches to gravity as a classical-only information channel. Here, we reconsider the current constraints on the DP model from spontaneous heating, by analyzing experimental situations not properly considered before. We argue that the the parameter-free version of the DP model is close to be ruled out by standard heat leak measurements at ultralow temperature, with a conclusive exclusion likely within reach with existing technology. This result would strengthen a recent claim of exclusion inferred by spontaneous x-ray emission experiments, which relies on the somewhat stronger assumption that the DP noise field is white up to x-ray frequencies.

上午9:47 | | | Iver Brevik, Boris Shapiro | | | quant-ph updates on arXiv.org |

The Casimir-Lifshitz force acts between neutral material bodies and is due to the fluctuations (around zero) of the electrical polarizations of the bodies. This force is a macroscopic manifestation of the van der Waals forces between atoms and molecules. There are two different approaches in the theory of this force. One is centered on the fluctuations inside the bodies, as the source of the fluctuational electromagnetic fields and forces. The second approach is based on finding the eigenmodes of the field, while the material bodies are assumed to be passive and non-fluctuating. Although both approaches have a long history, there are still some misconceptions in the literature. In particular, there are claims that (hypothetical) materials with a strictly real dielectric function $\varepsilon(\omega)$ can give rise to fluctuational Casimir-Lifshitz forces. We review and compare the two approaches, using the simple example of the force in the absence of retardation. We point out that also in the second (the “field-oriented”) approach one cannot avoid introducing an infinitesimal imaginary part into the dielectric function, i.e. introducing some dissipation. Furthermore, we emphasize that the requirement of analyticity of $ \varepsilon(\omega)$ in the upper half of the complex $\omega$ plane is not the only one for a viable dielectric function. In particular, models that use a strictly real $\varepsilon(\omega)$ (for all real positive $\omega)$ are inadmissible and lead to various contradictions and inconsistencies. Specifically, we present a critical discussion of the “dissipation-less plasma model”. Our emphasis is not on the most recent developments in the field but on some conceptual, not fully resolved issues.

上午9:47 | | | Pasquale Bosso, Giuseppe Gaetano Luciano | | | quant-ph updates on arXiv.org |

Several models of quantum gravity predict the emergence of a minimal length at Planck scale. This is commonly taken into consideration by modifying the Heisenberg Uncertainty Principle into the Generalized Uncertainty Principle. In this work, we study the implications of a polynomial Generalized Uncertainty Principle on the harmonic oscillator. We revisit both the analytic and algebraic methods, deriving the exact form of the generalized Heisenberg algebra in terms of the new position and momentum operators. We show that the energy spectrum and eigenfunctions are affected in a non-trivial way. Furthermore, a new set of ladder operators is derived which factorize the Hamiltonian exactly. The above formalism is finally exploited to construct a quantum field theoretic toy model based on the Generalized Uncertainty Principle.

Is the Universe actually holographic?. (arXiv:2109.15022v1 [hep-th])

上午9:47 | | | gr-qc updates on arXiv.org |

Authors: Haidar Sheikhahmadi

In this letter, we are going to reexamine the holographic dark energy concept that is proposed for cosmological applications. By considering precisely the bounds on the entropy arisen from lattice field theory on one side and Bekenstein-Hawking entropy of black holes on another side, it is shown that the so-called holographic dark energy can not be mimicked as easily as claimed in the literature. In addition, the limits which are discussed in the literature on the electron $(g-2)$ experiments, are rediscussed here. It is shown that the corrections to the electron magnetic momentum should be of the order of ${O}(10^{-23})$

上午9:47 | | | gr-qc updates on arXiv.org |

Authors: Fay Dowker, Henry Wilkes

We give an argument for strong positivity of the decoherence functional as the correct, physical positivity condition in formulations of quantum theory based fundamentally on the path integral. We extend to infinite systems work by Boes and Navascues that shows that the set of strongly positive quantum systems is maximal amongst sets of systems that are closed under tensor product composition. We show further that the set of strongly positive quantum systems is the unique set that is maximal amongst sets that are closed under tensor product composition.

On the relationship between geometric objects and figures in Euclidean geometry

2021年10月1日 星期五 上午5:06 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Bacelar Valente, Mario (2021) On the relationship between geometric objects and figures in Euclidean geometry. [Preprint]

Momentum Entanglement for Atom Interferometry

2021年9月29日 星期三 下午6:00 | | | F. Anders, A. Idel, P. Feldmann, D. Bondarenko, S. Loriani, K. Lange, J. Peise, M. Gersemann, B. Meyer-Hoppe, S. Abend, N. Gaaloul, C. Schubert, D. Schlippert, L. Santos, E. Rasel, and C. Klempt | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): F. Anders, A. Idel, P. Feldmann, D. Bondarenko, S. Loriani, K. Lange, J. Peise, M. Gersemann, B. Meyer-Hoppe, S. Abend, N. Gaaloul, C. Schubert, D. Schlippert, L. Santos, E. Rasel, and C. Klempt

Compared to light interferometers, the flux in cold-atom interferometers is low and the associated shot noise is large. Sensitivities beyond these limitations require the preparation of entangled atoms in different momentum modes. Here, we demonstrate a source of entangled atoms that is compatible w…

[Phys. Rev. Lett. 127, 140402] Published Wed Sep 29, 2021

There Is No Measurement Problem for Humeans

2021年9月29日 星期三 上午10:25 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Dorst, Chris (2021) There Is No Measurement Problem for Humeans. [Preprint]

On Two Different Kinds of Computational Indeterminacy

2021年9月29日 星期三 上午10:24 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Papayannopoulos, Philippos and Fresco, Nir and Shagrir, Oron (2021) On Two Different Kinds of Computational Indeterminacy. [Preprint]

2021年9月28日 星期二 下午3:52 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Merritt, David (2021) MOND and Methodology. Karl Popper’s Science and Philosophy. pp. 69-96.

2021年9月28日 星期二 下午3:52 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gasco, Enrico (2020) Einstein’s Wonder. Proceedings of the XL SISFA Conference, 2021. pp. 125-131.

Why Bell’s Everett (?) theory is wrong

2021年9月27日 星期一 下午1:58 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gao, Shan (2021) Why Bell’s Everett (?) theory is wrong. [Preprint]

Representation and the Quantum State

2021年9月27日 星期一 下午1:58 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Healey, Richard A. (2021) Representation and the Quantum State. [Preprint]

Laws as Epistemic Infrastructure not Metaphysical Superstructure

2021年9月27日 星期一 下午1:56 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Healey, Richard A. (2021) Laws as Epistemic Infrastructure not Metaphysical Superstructure. [Preprint]

States of Ignorance and Ignorance of States: Examining the Quantum Principal Principle

2021年9月27日 星期一 下午1:53 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Meehan, Alexander (2021) States of Ignorance and Ignorance of States: Examining the Quantum Principal Principle. [Preprint]

The Closure of the Physical is Unscientific

2021年9月26日 星期日 上午8:54 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Kleiner, Johannes and Stephan, Hartmann (2021) The Closure of the Physical is Unscientific. [Preprint]

Review of Causation in Science by Yemima Ben-Menahem

2021年9月26日 星期日 上午8:52 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Farr, Matt (2021) Review of Causation in Science by Yemima Ben-Menahem. [Preprint]

]]>上午8:00 | | | Latest Results for Synthese |

**Abstract**

I claim that objective consequentialism (OC) faces a problem stemming from the existence in some situations of a plurality of chances relevant to the outcomes of an agent’s acts. I suggest that this phenomenon bears structural resemblance to the well-known Reference Class problem. I outline a few ways in which one could attempt to deal with the issue, suggesting that it is the higher-level chance that should be employed by OC.

The non-ideal theory of the Aharonov–Bohm effect

上午8:00 | | | Latest Results for Synthese |

**Abstract**

Elay Shech and John Earman have recently argued that the common topological interpretation of the Aharonov–Bohm (AB) effect is unsatisfactory because it fails to justify idealizations that it presupposes. In particular, they argue that an adequate account of the AB effect must address the role of boundary conditions in certain ideal cases of the effect. In this paper I defend the topological interpretation against their criticisms. I consider three types of idealization that might arise in treatments of the effect. First, Shech takes the AB effect to involve an idealization in the form of a singular limit, analogous to the thermodynamic limit in statistical mechanics. But, I argue, the AB effect itself features no singular limits, so it doesn’t involve idealizations in this sense. Second, I argue that Shech and Earman’s emphasis on the role of boundary conditions in the AB effect is misplaced. The idealizations that are useful in connecting the theoretical description of the AB effect to experiment do interact with facts about boundary conditions, but none of these idealizations are presupposed by the topological interpretation of the effect. Indeed, the boundary conditions for which Shech and demands justification are incompatible with some instances of the AB effect, so the topological interpretation ought not justify them. Finally, I address the role of the non-relativistic approximation usually presumed in discussions of the AB effect. This approximation is essential if—as the topological interpretation supposes—the AB effect constrains and justifies a relativistic theory of the electromagnetic interaction. In this case the ends justify the means. So the topological view presupposes no unjustified idealizations.

Effective theories and infinite idealizations: a challenge for scientific realism

上午8:00 | | | Latest Results for Synthese |

**Abstract**

Williams and J. Fraser have recently argued that effective field theory methods enable scientific realists to make more reliable ontological commitments in quantum field theory (QFT) than those commonly made. In this paper, I show that the interpretative relevance of these methods extends beyond the specific context of QFT by identifying common structural features shared by effective theories across physics. In particular, I argue that effective theories are best characterized by the fact that they contain intrinsic empirical limitations, and I extract from their structure one central interpretative constraint for making more reliable ontological commitments in different subfields of physics. While this is in principle good news, this constraint still raises a challenge for scientific realists in some contexts, and I bring the point home by focusing on Williams’s and J. Fraser’s defense of selective realism in QFT.

Work done in a decoherence process. (arXiv:2109.09135v2 [quant-ph] UPDATED)

上午10:05 | | | Gianluca Francica | | | quant-ph updates on arXiv.org |

We investigate the thermodynamics of a quench realized by turning on an interaction generating pure decoherence. We characterize the work probability distribution function, also with a fluctuation relation, a lower bound of the work and by considering some physical examples.

上午10:05 | | | Hendra I. Nurdin, John E. Gough | | | quant-ph updates on arXiv.org |

A general theory of quantum stochastic processes was formulated by Accardi, Frigerio and Lewis in 1982 within the operator-algebraic framework of quantum probability theory, as a non-commutative extension of the Kolmogorovian classical stochastic processes. More recently, studies on non-Markovian quantum processes have led to the discrete-time process tensor formalism in the Schr\”{o}dinger picture to describe the outcomes of sequential interventions on open quantum systems. However, there has been no treatment of the relationship of the process tensor formalism to the quantum probabilistic theory of quantum stochastic processes. This paper gives an exposition of quantum stochastic processes and the process tensor and the relationship between them. In particular, it is shown how the latter emerges from the former via extended correlation kernels incorporating ancillas.

上午10:05 | | | physics.hist-ph updates on arXiv.org |

Authors: Indrajit Sen

In a recent article (arXiv:2108.08144), Hance, Hossenfelder and Palmer have advanced arguments claiming to show that the analysis of Invariant-set theory in a hidden-variable setting (arXiv:2107.04761) is wrong. We explain here why these arguments are incorrect, and involve misunderstandings of the hidden-variable model in question and Bell’s notion of local causality.

上午10:05 | | | physics.hist-ph updates on arXiv.org |

Authors: Zhi-Wei Wang, Samuel L. Braunstein

It is hard to look at the universe and not wonder about the meaning, of, well, everything. A natural question is whether what we see is a sign of intelligent design. The antithesis of design would be a random universe or, assuming laws of physics, one whose fundamental physical parameters were randomly selected, but conditioned on life (ourselves) being here to observe it. In unpublished work, the British physicist Dennis Sciama argued that such a randomly selected universe would display a statistical signature. He concluded that a random universe would almost certainly have parameters only just allowing for the possibility of life. Here we consider whether this signature is definitive. We find that with plausible additional assumptions Sciama’s signature would appear to reverse: Were our universe random, it could give the false impression of being intelligently designed, with the fundamental constants appearing to be fine-tuned to a strong probability for life to emerge and be maintained.

On the energy of gravitational waves. (arXiv:2109.06864v2 [gr-qc] UPDATED)

上午10:05 | | | gr-qc updates on arXiv.org |

Authors: Rong-Gen Cai, Xing-Yu Yang, Long Zhao

The energy of gravitational waves (GWs) is a fundamental problem in gravity theory. The existing descriptions for the energy of GWs, such as the well-known Isaacson energy-momentum tensor, suffer from several defects. Due to the equivalence principle, the gravitational energy-momentum can only be defined quasilocally, being associated with a closed spacelike 2-surface bounding a region. We propose a new approach to derive the energy of GWs directly from the quasilocal gravitational energy. Such an approach is natural and consistent with the quasilocality of gravitational energy-momentum, and it is valid for GWs with any wavelengths in any order of perturbations.

Quantum Hypothesis Testing for Exoplanet Detection

2021年9月23日 星期四 下午6:00 | | | Zixin Huang and Cosmo Lupo | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Zixin Huang and Cosmo Lupo

Treating stars and planets as quantum objects could make it easier for astronomers to directly image exoplanets.

[Phys. Rev. Lett. 127, 130502] Published Thu Sep 23, 2021

ΛCDM and MOND: A Debate about Models or Theory?

2021年9月22日 星期三 下午4:19 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Jacquart, Melissa (2021) ΛCDM and MOND: A Debate about Models or Theory? [Preprint]

When do Gibbsian Phase Averages and Boltzmannian Equilibrium Values Agree?

2021年9月21日 星期二 下午3:06 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Werndl, Charlotte and Frigg, Roman (2020) When do Gibbsian Phase Averages and Boltzmannian Equilibrium Values Agree? [Preprint]

The Process Metaphysics of Loop Quantum Gravity

2021年9月21日 星期二 下午3:03 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Calamari, Martin (2021) The Process Metaphysics of Loop Quantum Gravity. UNSPECIFIED.

Governing Without A Fundamental Direction of Time: Minimal Primitivism about Laws of Nature

2021年9月21日 星期二 下午3:01 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Chen, Eddy Keming and Goldstein, Sheldon (2021) Governing Without A Fundamental Direction of Time: Minimal Primitivism about Laws of Nature. [Preprint]

2021年9月21日 星期二 下午2:58 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

ROVELLI, Carlo The Relational Interpretation. UNSPECIFIED.

The Measurement Problem of Consciousness (Preprint)

2021年9月21日 星期二 下午2:57 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Browning, Heather and Veit, Walter (2021) The Measurement Problem of Consciousness (Preprint). [Preprint]

Logic, Philosophy and Physics: A Critical Commentary on the Dilemma of Categories

2021年9月18日 星期六 下午4:35 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Majhi, Abhishek (2021) Logic, Philosophy and Physics: A Critical Commentary on the Dilemma of Categories. Axiomathes. ISSN 1572-8390

Scientific Progress and Aesthetic Values

2021年9月18日 星期六 下午4:34 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Ivanova, Milena (2021) Scientific Progress and Aesthetic Values. [Preprint]

Three facets of time-reversal symmetry

2021年9月18日 星期六 下午4:34 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

López, Cristian (2021) Three facets of time-reversal symmetry. [Preprint]

Time’s Direction and Orthodox Quantum Mechanics: Time Symmetry and Measurement

2021年9月18日 星期六 下午4:33 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Lopez, Cristian (2021) Time’s Direction and Orthodox Quantum Mechanics: Time Symmetry and Measurement. [Preprint]

The Physics and the Philosophy of Time Reversal in Standard Quantum Mechanics

2021年9月18日 星期六 下午4:33 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Lopez, Cristian (2021) The Physics and the Philosophy of Time Reversal in Standard Quantum Mechanics. [Preprint]

Neo-Lorentzian Relativity and the Beginning of the Universe

2021年9月18日 星期六 下午4:30 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Linford, Daniel (2021) Neo-Lorentzian Relativity and the Beginning of the Universe. [Preprint]

]]>上午9:32 | | | Alisson Tezzin | | | quant-ph updates on arXiv.org |

Recent research on quantum contextuality has been strongly centered on device-independent frameworks, such as the many graph approaches to contextuality and the celebrated sheaf-theoretical approach. Contextuality is described in these frameworks as a property of data only, making it possible to characterize and quantify the phenomena regardless of the reasons why it occurs. In this paper we look beyond the data and focus on possible explanations for this experimental fact. We show that a classical system generating contextual data can easily be found if the following conditions are satisfied (1) We only have access to a specific collection of “epistemic” measurements (which, all things considered, is basically Bohr’s view on quantum measurements) and (2) There is a limitation on which of these measurements can be jointly performed. The way we see it, this example indicates that contextuality may be a consequence of the type of measurement taken into account, instead of an intrinsic feature of the system upon which these measurements are performed; if this is correct, the widespread idea that quantum contextuality is a non-classical feature can be avoided.

上午9:32 | | | Francois-Igor Pris | | | quant-ph updates on arXiv.org |

We argue that Anton Zeilinger’s “foundational conceptual principle” for quantum mechanics according to which an elementary system carries one bit of information is an idealistic principle, which should be replaced by a realistic principle of contextuality. Specific properties of quantum systems are a consequence of impossibility to speak about them without reference to the tools of their observation/identification and, consequently, context in which these tools are applied.

上午9:32 | | | Clement Mawby, Jonathan Halliwell | | | quant-ph updates on arXiv.org |

Macrorealism (MR) is the world-view that at all moments of time, a system is definitely in one of the observable states available to it, irrespective of past or future measurements. The Leggett-Garg (LG) inequalities were introduced to test MR and assess for the presence of macroscopic quantum coherence. Since such effects could plausibly be found in various types of macroscopic oscillators, we apply the LG approach to the quantum harmonic oscillator (QHO) and more general bound systems, using a single dichotomic variable Q given by the sign of the oscillator position. We present a simple method to calculate the relevant temporal correlators for any bound system for which the energy eigenspectrum is (exactly or numerically) known. We then apply this result to the QHO for a variety of experimentally accessible states, namely energy eigenstates, and superpositions thereof. For the subspace of states spanned by only the ground state and first excited state, we readily find substantial regions of parameter space in which the two and three-time LG inequalities can each be independently violated or satisfied. We find violations persist (although are reduced) when the sign function defining Q is smeared to reflect experimental imprecision. We also find that LG violations diminish at high energies, showing the expected classicalization. With a Q defined as an arbitrary position coarse graining, we find two-time LG violations even in the ground state, a simple example of a feature recently noted by Bose et al. [Phys. Rev. Lett. 120, 210402 (2018)]. We also show that two-time LG violations in a gaussian state are readily found if the dichotomic variable at one of the times is taken to be the parity operator. To demonstrate the versatility of the technique we developed, we perform an LG analysis for the Morse potential, where we find significant violations for the first excited state.

上午9:32 | | | gr-qc updates on arXiv.org |

Authors: Deaglan J. Bartlett, Harry Desmond, Pedro G. Ferreira, Jens Jasche

Lorentz Invariance Violation in Quantum Gravity (QG) models or a non-zero photon mass, $m_\gamma$, would lead to an energy-dependent propagation speed for photons, such that photons of different energies from a distant source would arrive at different times, even if they were emitted simultaneously. By developing source-by-source, Monte Carlo-based forward models for such time delays from Gamma Ray Bursts, and marginalising over empirical noise models describing other contributions to the time delay, we derive constraints on $m_\gamma$ and the QG length scale, $\ell_{\rm QG}$, using spectral lag data from the BATSE satellite. We find $m_\gamma < 4.0 \times 10^{-5} \, h \, {\rm eV}/c^2$ and $\ell_{\rm QG} < 5.3 \times 10^{-18} \, h \, {\rm \, GeV^{-1}}$ at 95% confidence, and demonstrate that these constraints are robust to the choice of noise model. The QG constraint is among the tightest from studies which consider multiple Gamma Ray Bursts and the constraint on $m_\gamma$, although weaker than from using radio data, provides an independent constraint which is less sensitive to the effects of dispersion by electrons.

Comment on “Maximum force and cosmic censorship”. (arXiv:2109.07700v1 [gr-qc])

上午9:32 | | | gr-qc updates on arXiv.org |

Authors: Christoph Schiller

Despite suggestions to the contrary, no counterargument to the principle of maximum force or to the equivalent principle of maximum power has yet been provided.

Can the Hubble tension be resolved by bulk viscosity?. (arXiv:2107.13533v2 [gr-qc] UPDATED)

上午9:32 | | | gr-qc updates on arXiv.org |

Authors: Ben David Normann, Iver Håkon Brevik

We show that the cosmic bulk viscosity estimated in our previous works is sufficient to bridge the $H_0$ value inferred from observations of the early universe with the value inferred from the local (late) universe.

A computational complexity approach to the definition of empirical equivalence.

2021年9月17日 星期五 上午6:44 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Brogioli, Doriano (2019) A computational complexity approach to the definition of empirical equivalence. [Preprint]

Two Quantum Logics of Indeterminacy

2021年9月17日 星期五 上午6:43 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Fletcher, Samuel C. and Taylor, David E. (2021) Two Quantum Logics of Indeterminacy. Synthese. ISSN 1573-0964

Can Redescriptions of Outcomes Salvage the Axioms of Decision Theory?

2021年9月17日 星期五 上午6:41 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Baccelli, Jean and Mongin, Philippe (2021) Can Redescriptions of Outcomes Salvage the Axioms of Decision Theory? Philosophical Studies. ISSN 0031-8116

Maxwell’s Demon in Quantum Mechanics

2021年9月17日 星期五 上午6:40 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Hemmo, Meir and Shenker, Orly R. (2020) Maxwell’s Demon in Quantum Mechanics. Entropy, 22. p. 269. ISSN 1099-4300

Macroscopically Nonlocal Quantum Correlations

2021年9月16日 星期四 下午6:00 | | | Miguel Gallego and Borivoje Dakić | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Miguel Gallego and Borivoje Dakić

It is usually believed that coarse graining of quantum correlations leads to classical correlations in the macroscopic limit. Such a principle, known as macroscopic locality, has been proved for correlations arising from independent and identically distributed (IID) entangled pairs. In this Letter, …

[Phys. Rev. Lett. 127, 120401] Published Thu Sep 16, 2021

Consciousness, Phenomenal Consciousness, and Free Will

2021年9月15日 星期三 下午12:39 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Sytsma, Justin and Snater, Melissa (2021) Consciousness, Phenomenal Consciousness, and Free Will. [Preprint]

We Cannot Allow a Wikipedia Gap!

2021年9月12日 星期日 下午3:38 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Ross, Sage Rogers (2007) We Cannot Allow a Wikipedia Gap! Spontaneous Generations: A Journal for the History and Philosophy of Science, 1 (1). ISSN 1913-0465

]]>上午9:54 | | | Mario A. Quiroz-Juárez, Zachary A. Cochran, José L. Aragón, Yogesh N. Joglekar, Roberto de J. León-Montiel | | | quant-ph updates on arXiv.org |

Parity-Time (PT) symmetric systems have been widely recognized as fundamental building blocks for the development of novel, ultra-sensitive opto-electronic devices. However, arguably one of their major drawbacks is that they rely on non-linear amplification processes that could limit their potential applications, particularly in the quantum realm. In this work, we show both theoretically and experimentally that gain-loss, PT-symmetric systems can be designed by means of linear, time-modulated components. More specifically, by making use of a state-of-the-art, fully reconfigurable electronic platform, we demonstrate that PT-symmetry breaking transitions can be observed by properly modulating the inductance (L) and the capacitance (C) of a single LC circuit. Importantly, the lossless dynamic-variations of the electrical components used in our LC circuits allow us to control the static and periodic (Floquet) regimes of our PT-symmetric system. Our results challenge the conventional wisdom that at least two-oscillator systems are needed for observing PT-symmetric phenomena, and provide a new perspective in the field of synthetic PT symmetry with important implications for sensing, energy transfer and topology.

Violation $\neq$ Quantum. (arXiv:2109.03871v1 [quant-ph])

上午9:54 | | | Xingyu Guo, Chen-Te Ma | | | quant-ph updates on arXiv.org |

The only entanglement quantity is concurrence in a 2-qubit pure state. The maximum violation of Bell’s inequality is monotonically increasing for this quantity. Therefore, people expect that pure state entanglement is relevant to the quantum violation. To understand the relation between violation and entanglement, we extend the study to three qubits. We consider all possible 3-qubit operators with a symmetric permutation. When only turning on one entanglement measure, the numerical result shows a contradiction to the expectation. The maximum violation does not have the same behavior as in 2-qubit pure states. Therefore, we conclude “Violation$\neq$Quantum”. In the end, we propose the generalized $R$-matrix or correlation matrix for the new diagnosis of Quantum Entanglement. We demonstrate the evidence by restoring the monotonically increasing result.

Spooky action at a distance also acts in the past. (arXiv:2109.04151v1 [quant-ph])

上午9:54 | | | Mandip Singh | | | quant-ph updates on arXiv.org |

The term `spooky action at a distance’ was coined by A. Einstein to show inconsistency of quantum mechanics with the principle of locality and reality. However, quantum mechanics is nonlocal and violates Bell’s inequality. A quantum state measurement of a particle of an entangled pair collapses the total quantum state and the quantum state of the distant particle is immediately determined without making any interaction with it. The isolated collapsed quantum state of both particles remains unentangled in the future. An inertial frame of reference moving with a relativistic speed perceives these events differently is space and time and their simultaneity is relative. In this paper, it is shown that the quantum state collapse happens not only in the present but it also happens in the past of the collapse event.

上午9:54 | | | Guillaume Aubrun, Ludovico Lami, Carlos Palazuelos, Martin Plávala | | | quant-ph updates on arXiv.org |

We prove that any two general probabilistic theories (GPTs) are entangleable, in the sense that their composite exhibits either entangled states or entangled measurements, if and only if they are both non-classical, meaning that neither of the state spaces is a simplex. This establishes the universal equivalence of the (local) superposition principle and the existence of global entanglement, valid in a fully theory-independent way. As an application of our techniques, we show that all non-classical GPTs exhibit a strong form of incompatibility of states and measurements, and use this to construct a version of the BB84 protocol that works in any non-classical GPT.

General Relativity’s energy and positivity — a brief history. (arXiv:2109.03936v1 [physics.hist-ph])

上午9:54 | | | physics.hist-ph updates on arXiv.org |

Authors: S.Deser

I give a brief review of the search for a proper definition of energy in General Relativity (GR), a far from trivial quest, which was only completed after four and a half decades. The equally (or perhaps more) difficult task of establishing its positivity — it was to take another fifteen plus years — will then be summarized. Extension to cosmological GR is included. Mention is made of some recent offshoots.

Chaos-protected locality. (arXiv:2109.03825v1 [quant-ph])

上午9:54 | | | gr-qc updates on arXiv.org |

Authors: Shao-Kai Jian, Brian Swingle

Microscopic speed limits that constrain the motion of matter, energy, and information abound in physics, from the “ultimate” speed limit set by light to Lieb-Robinson speed limits in quantum spin systems. In addition to these state-independent speed limits, systems can also be governed by emergent state-dependent speed limits indicating slow dynamics arising, for example, from slow low-energy quasiparticles. Here we describe a different kind of speed limit: a situation where complex information/entanglement spreads rapidly, in a fashion inconsistent with any speed limit, but where simple signals continue to obey an approximate speed limit. If we take the point of view that the motion of simple signals defines the local spacetime geometry of the universe, then the effects we describe show that spacetime locality can be compatible with a high degree of non-local interactions provided these are sufficiently chaotic. With this perspective, we sharpen a puzzle about black holes recently raised by Shor and propose a schematic resolution.

What actually happens when you approach a gravitational singularity?. (arXiv:2109.04061v1 [gr-qc])

上午9:54 | | | gr-qc updates on arXiv.org |

Authors: Susan M. Scott, Ben E. Whale

Roger Penrose’s 2020 Nobel Prize in Physics recognises that his identification of the concepts of “gravitational singularity” and an “incomplete, inextendible, null geodesic” is physically very important. The existence of an incomplete, inextendible, null geodesic doesn’t say much, however, if anything, about curvature divergence, nor is it a helpful definition for performing actual calculations. Physicists have long sought for a coordinate independent method of defining where a singularity is located, given an incomplete, inextendible, null geodesic, that also allows for standard analytic techniques to be implemented. In this essay we present a solution to this issue. It is now possible to give a concrete relationship between an incomplete, inextendible, null geodesic and a gravitational singularity, and to study any possible curvature divergence using standard techniques.

上午9:54 | | | gr-qc updates on arXiv.org |

Authors: Bodo Lampe

The cosmic time dependencies of $G$, $\alpha$, $\hbar$ and of Standard Model parameters like the Higgs vev and elementary particle masses are studied in the framework of a new dark energy interpretation. Due to the associated time variation of rulers, many effects turn out to be invisible. However, a rather large time dependence is claimed to arise in association with dark energy measurements, and smaller ones in connection with the Standard Model.

上午6:00 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Mitsch, Chris (2021) Hilbert-Style Axiomatic Completion: The (Not So) Hidden Contextuality of von Neumann’s “No Hidden Variables” Theorem. [Preprint]

Quantum Theory Cannot Violate a Causal Inequality

2021年9月10日 星期五 下午6:00 | | | Tom Purves and Anthony J. Short | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Tom Purves and Anthony J. Short

Within quantum theory, we can create superpositions of different causal orders of events, and observe interference between them. This raises the question of whether quantum theory can produce results that would be impossible to replicate with any classical causal model, thereby violating a causal in…

[Phys. Rev. Lett. 127, 110402] Published Fri Sep 10, 2021

Bipartite Measurements in Minkowski Space

2021年9月10日 星期五 上午7:17 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

King, Robbie (2021) Bipartite Measurements in Minkowski Space. [Preprint]

2021年9月10日 星期五 上午7:15 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Leifer, Matthew Saul (2016) A. Douglas Stone. Einstein and the Quantum: The Quest of the Valiant Swabian. 332 pp. Princeton University Press, 2013. Spontaneous Generations: A Journal for the History and Philosophy of Science, 8 (1). pp. 105-108. ISSN 1913-0465

Maxwellian Electrodynamics Genesis and Development: Intertheoretic Context

2021年9月10日 星期五 上午1:05 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Nugayev, Rinat Magdievich (2016) Maxwellian Electrodynamics Genesis and Development: Intertheoretic Context. Spontaneous Generations: A Journal for the History and Philosophy of Science, 8 (1). pp. 55-92. ISSN 1913-0465

2021年9月8日 星期三 上午8:00 | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 08 September 2021; doi:10.1038/s41567-021-01362-5

The European Researchers’ Night provides a platform for scientists to engage with the public.

2021年9月8日 星期三 上午8:00 | | | Richard Brierley | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 08 September 2021; doi:10.1038/s41567-021-01353-6

Even more exotic

Interaction-Free Measurement with Electrons

2021年9月7日 星期二 下午6:00 | | | Amy E. Turner, Cameron W. Johnson, Pieter Kruit, and Benjamin J. McMorran | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Amy E. Turner, Cameron W. Johnson, Pieter Kruit, and Benjamin J. McMorran

Here, we experimentally demonstrate interaction-free measurements with electrons using a novel electron Mach-Zehnder interferometer. The flexible two-grating electron interferometer is constructed in a conventional transmission electron microscope and achieves high contrast in discrete output detect…

[Phys. Rev. Lett. 127, 110401] Published Tue Sep 07, 2021

Four-dimensionalism, eternalism, and deprivationist accounts of the evil of death

2021年9月7日 星期二 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Four-dimensionalists think that we persist over time by having different temporal parts at each of the times at which we exist. Eternalists think that all times are equally real. Deprivationists think that death is an evil for the one who dies because it deprives them of something. I argue that four-dimensionalist eternalism, conjoined with a standard deprivationist account of the evil of death, has surprising implications for what we should think about the evil of death. In particular, given these assumptions, we will lack any grounds for thinking that death is an evil for some individuals for whom we would antecedently expect it to be an evil, namely those individuals who cease to exist at death. Alternatively, we will only have some grounds for thinking that death is an evil for certain individuals for whom we might antecedently be more inclined to think death is not an evil, namely those individuals who survive death, in the sense that they continue to exist after death.

A paradox about sets of properties

2021年9月6日 星期一 上午8:00 | | | Latest Results for Synthese |

**Abstract**

A paradox about sets of properties is presented. The paradox, which invokes an impredicatively defined property, is formalized in a free third-order logic with lambda-abstraction, through a classically proof-theoretically valid deduction of a contradiction from a single premise to the effect that every property has a unit set. Something like a model is offered to establish that the premise is, although classically inconsistent, nevertheless consistent, so that the paradox discredits the logic employed. A resolution through the ramified theory of types is considered. Finally, a general scheme that generates a family of analogous paradoxes and a generally applicable resolution are proposed.

]]>上午10:13 | | | David Edward Bruschi, Andreas W. Schell | | | quant-ph updates on arXiv.org |

We use quantum field theory in curved spacetime to show that gravitational redshift induces a unitary transformation on the quantum state of propagating photons. This occurs for realistic photons characterized by a finite bandwidth, while ideal photons with sharp frequencies do not transform unitarily. We find that the transformation is a mode-mixing operation, and we devise a protocol that exploits gravity to induce a Hong-Ou-Mandel-like interference effect on the state of two photons. Testing the results of this work can provide a demonstration of quantum field theory in curved spacetime.

Causal structure in spin-foams. (arXiv:2109.00986v1 [gr-qc])

上午10:13 | | | Eugenio Bianchi, Pierre Martin-Dussaud | | | quant-ph updates on arXiv.org |

The metric field of general relativity is almost fully determined by its causal structure. Yet, in spin-foam models for quantum gravity, the role played by the causal structure is still largely unexplored. The goal of this paper is to clarify how causality is encoded in such models. The quest unveils the physical meaning of the orientation of the two-complex and its role as a dynamical variable. We propose a causal version of the EPRL spin-foam model and discuss the role of the causal structure in the reconstruction of a semiclassical spacetime geometry.

The Future of Quantum Theory: A Way Out of the Impasse. (arXiv:2109.01028v1 [quant-ph])

上午10:13 | | | Ghislain Fourny | | | quant-ph updates on arXiv.org |

In this letter, we point to three widely accepted challenges that the quantum theory, quantum information, and quantum foundations communities are currently facing: indeterminism, the semantics of conditional probabilities, and the spooky action at a distance. We argue that these issues are fundamentally rooted in conflations commonly made between causal dependencies, counterfactual dependencies, and statistical dependencies. We argue that a simple, albeit somewhat uncomfortable shift of viewpoint leads to a way out of the impossibility to extend the theory beyond indeterminism, and towards the possibility that sound extensions of quantum theory, possibly even deterministic yet not super-deterministic, will emerge in the future. The paradigm shift, which we present here, involves a non-trivial relaxation of the commonly accepted mathematical definition of free choice, leading to non-Nashian free choice, more care with the choice of probabilistic notations, and more rigorous use of vocabulary related to causality, counterfactuals, and correlations, which are three concepts of a fundamentally different nature.

上午10:13 | | | V. S. Gomes, P. R. Dieguez, H. M. Vasconcelos | | | quant-ph updates on arXiv.org |

The realism-based nonlocality (RBN) is a recently introduced measure that differs from the well-known Bell’s nonlocality. For bipartite states, the RBN concerns how much an element of reality associated with a given observable is affected upon local measurements on a subsystem. Here, we present an analytical proof for the unitary invariance of the RBN and that it presents a monotonous behavior upon the action of unital and non-unital local quantum noise. We illustrate our results by employing the two-qubits Werner state and thermal quantum correlated states. We show how the RBN is limited by the initial equilibrium temperature and, especially, that it decays asymptotically with it. These results also corroborate the hierarchy relationship between the quantifiers of RBN and global quantum discord, showing that RBN can capture undetectable nonlocal aspects even for non-discordant states. Finally, we argue how our results can be employed to use the RBN as a security tool in quantum communication tasks.

The Autodidactic Universe. (arXiv:2104.03902v2 [hep-th] UPDATED)

上午10:13 | | | Stephon Alexander, William J. Cunningham, Jaron Lanier, Lee Smolin, Stefan Stanojevic, Michael W. Toomey, Dave Wecker | | | quant-ph updates on arXiv.org |

We present an approach to cosmology in which the Universe learns its own physical laws. It does so by exploring a landscape of possible laws, which we express as a certain class of matrix models. We discover maps that put each of these matrix models in correspondence with both a gauge/gravity theory and a mathematical model of a learning machine, such as a deep recurrent, cyclic neural network. This establishes a correspondence between each solution of the physical theory and a run of a neural network. This correspondence is not an equivalence, partly because gauge theories emerge from $N \rightarrow \infty $ limits of the matrix models, whereas the same limits of the neural networks used here are not well-defined. We discuss in detail what it means to say that learning takes place in autodidactic systems, where there is no supervision. We propose that if the neural network model can be said to learn without supervision, the same can be said for the corresponding physical theory. We consider other protocols for autodidactic physical systems, such as optimization of graph variety, subset-replication using self-attention and look-ahead, geometrogenesis guided by reinforcement learning, structural learning using renormalization group techniques, and extensions. These protocols together provide a number of directions in which to explore the origin of physical laws based on putting machine learning architectures in correspondence with physical theories.

Which way does stimulated emission go?. (arXiv:2108.13943v2 [physics.optics] UPDATED)

上午10:13 | | | J. David Wong-Campos, Trey Porto, Adam E. Cohen | | | quant-ph updates on arXiv.org |

Is it possible to form an image using light produced by stimulated emission? Here we study light scatter off an assembly of excited chromophores. Due to the Optical Theorem, stimulated emission is necessarily accompanied by excited state Rayleigh scattering. Both processes can be used to form images, though they have different dependencies on scattering direction, wavelength and chromophore configuration. Our results suggest several new approaches to optical imaging using fluorophore excited states.

上午10:13 | | | physics.hist-ph updates on arXiv.org |

Authors: Marco Di Mauro, Salvatore Esposito, Adele Naddeo

Richard P. Feynman’s work on gravitation, as can be inferred from several published and unpublished sources, is reviewed. Feynman was involved with this subject at least from late 1954 to the late 1960s, giving several pivotal contributions to it. Even though he published only three papers, much more material is available, beginning with the records of his many interventions at the Chapel Hill conference in 1957, which are here analyzed in detail, and show that he had already considerably developed his ideas on gravity. In addition he expressed deep thoughts about fundamental issues in quantum mechanics which were suggested by the problem of quantum gravity, such as superpositions of the wave functions of macroscopic objects and the role of the observer. Feynman also lectured on gravity several times. Besides the famous lectures given at Caltech in 1962-63, he extensively discussed this subject in a series of lectures delivered at the Hughes Aircraft Company in 1966-67, whose focus was on astronomy and astrophysics. All this material allows to reconstruct a detailed picture of Feynman’s ideas on gravity and of their evolution until the late sixties. According to him, gravity, like electromagnetism, has quantum foundations, therefore general relativity has to be regarded as the classical limit of an underlying quantum theory; this quantum theory should be investigated by computing physical processes, as if they were experimentally accessible. The same attitude is shown with respect to gravitational waves, as is evident also from an unpublished letter addressed to Victor F. Weisskopf. In addition, an original approach to gravity, which closely mimics (and probably was inspired by) the derivation of the Maxwell equations given by Feynman in that period, is sketched in the unpublished Hughes lectures.

上午10:13 | | | physics.hist-ph updates on arXiv.org |

Authors: M.A. Natiello, Hernán G Solari

The force exerted by an electromagnetic body on another body in relative motion, and its minimal expression, the force on moving charges or \emph{Lorentz’ force} constitute the link between electromagnetism and mechanics. Expressions for the force were produced first by Maxwell and later by H. A. Lorentz, but their expressions disagree. The construction process was the result, in both cases, of analogies rooted in the idea of the ether. Yet, the expression of the force has remained despite its production context. We present a path to the electromagnetic force that starts from Ludwig Lorenz’ relational electromagnetism. The present mathematical abduction does not rest on analogies. Following this path we show that relational electromagnetism, as pursued by the G\”ottingen school, is consistent with Maxwell’s transformation laws and compatible with the idea that the “speed of light” takes the same value in all (inertial) frames of reference, while it cannot be conceived on the basis of analogies with material motion.

上午10:13 | | | gr-qc updates on arXiv.org |

Authors: Matteo Luca Ruggiero, Sara Mattiello, Matteo Leone

Why is modern physics still today, more than 100 years after its birth, the privilege of an elite of scientists and unknown for the great majority of citizens? The answer is simple, since modern physics is in general not present in the standard physics curricula, except for some general outlines, in the final years of some secondary schools. But, is it possibile to teach modern physics in primary school? Is it effective? And, also, is it engaging for students? These are the simple questions which stimulated our research, based on an intervention performed in the last year of Italian primary school, focused on teaching gravity, according to the Einsteinian approach in the spirit of the Einstein First project, an international collaboration which aims to teach school age children the concepts of modern physics. The outcomes of our research study are in agreement with previous findings obtained in Australian schools, thus they contribute to validate them and show that there is no cultural effect, since the approach works in different education systems. Finally, our results are relevant also in terms of retention and prove that the students involved really understand the key ideas.

Celestial Holography: Lectures on Asymptotic Symmetries. (arXiv:2109.00997v1 [hep-th])

上午10:13 | | | gr-qc updates on arXiv.org |

Authors: P. B. Aneesh, Geoffrey Compère, Leonardo Pipolo de Gioia, Igor Mol, Bianca Swidler

The aim of these Lectures is to provide a brief overview of the subject of asymptotic symmetries of gauge and gravity theories in asymptotically flat spacetimes as background material for celestial holography.

Popper and the Propensity Interpretation of Probability

上午12:32 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Pence, Charles H. (2021) Popper and the Propensity Interpretation of Probability. [Preprint]

A discussion on the origin of quantum probabilities

2021年9月2日 星期四 下午2:32 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Holik, Federico and Plastino, Angelo and Sáenz, Manuel (2013) A discussion on the origin of quantum probabilities. Annals of Physics, 340 (1). pp. 293-310.

On the assumptions underlying KS-like contradictions

2021年9月2日 星期四 下午2:31 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

de Barros, José Acacio and Jorge, Juan Pablo and Holik, Federico (2021) On the assumptions underlying KS-like contradictions. [Preprint]

Indistinguishability right from the start in standard quantum mechanics

2021年9月2日 星期四 下午2:30 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Holik, Federico and Jorge, Juan Pablo and Massri, César (2020) Indistinguishability right from the start in standard quantum mechanics. [Preprint]

Is the life-world reduction sufficient in quantum physics ?

2021年8月31日 星期二 下午4:02 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Bitbol, Michel (2021) Is the life-world reduction sufficient in quantum physics ? Continental Philosophy Review.

A PHENOMENOLOGICAL ONTOLOGY FOR PHYSICS: Merleau-Ponty and QBism

2021年8月31日 星期二 下午4:00 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Bitbol, Michel (2020) A PHENOMENOLOGICAL ONTOLOGY FOR PHYSICS: Merleau-Ponty and QBism.

A computational complexity approach to the definition of empirical equivalence.

2021年8月31日 星期二 下午3:58 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Brogioli, Doriano (2019) A computational complexity approach to the definition of empirical equivalence. [Preprint]

On the pragmatic and epistemic virtues of inference to the best explanation

2021年8月29日 星期日 上午8:00 | | | Latest Results for Synthese |

**Abstract**

In a series of papers over the past twenty years, and in a new book, Igor Douven (sometimes in collaboration with Sylvia Wenmackers) has argued that Bayesians are too quick to reject versions of inference to the best explanation that cannot be accommodated within their framework. In this paper, I survey their worries and attempt to answer them using a series of pragmatic and purely epistemic arguments that I take to show that Bayes’ Rule really is the only rational way to respond to your evidence.

J.R. Hance, S. Hossenfelder, T.N. Palmer

Bell’s theorem is often said to imply that quantum mechanics violates local causality, and that local causality cannot be restored with a hidden-variables theory. This however is only correct if the hidden-variables theory fulfils an assumption called Statistical Independence. Violations of Statistical Independence are commonly interpreted as correlations between the measurement settings and the hidden variables (which determine the measurement outcomes). Such correlations have been discarded as “finetuning” or a “conspiracy”. We here point out that the common interpretation is at best physically ambiguous and at worst incorrect. The problem with the common interpretation is that Statistical Independence might be violated because of a non-trivial measure in state space, a possibility we propose to call “supermeasured”. We use Invariant Set Theory as an example of a supermeasured theory that violates the Statistical Independence assumption in Bell’s theorem without requiring correlations between hidden variables and measurement settings.

This paper draws on a number of Roger Penrose’s ideas – including the non-Hamiltonian phase-space flow of the Hawking Box, Conformal Cyclic Cosmology, non-computability and gravitationally induced quantum state reduction – in order to propose a radically unconventional approach to quantum gravity: Invariant Set Theory (IST). In IST, the fundamental laws of physics describe the geometry of the phase portrait of the universe as a whole: “quantum” process are associated with fine-scale fractal geometry, “gravitational” process with larger-scale heterogeneous geometry. With this, it becomes possible to explain the experimental violation of Bell Inequalities without having to abandon key ingredients of general relativity: determinism and local causality. Ensembles in IST can be described by complex Hilbert states over a finite set Cp of complex numbers, where p is a large finite integer. The quantum mechanics of finite-dimensional Hilbert spaces is emergent as a singular limit when p→∞. A small modification to the field equations of general relativity is proposed to make it consistent with IST.

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