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Tomer Shushi

Fri Aug 02 2024 14:22:44 (21 hours)

# 1.

arXiv:2408.00046v1 Announce Type: new Abstract: One of the main issues in measuring the speed of light when it only travels from one spatial position into another position, known as the one-way speed of light, is that the clocks belonging to each separated spatial position are not and, in principle, cannot be synchronized with sufficient precision. This issue is the main reason why all of the measurements of the speed of light until now have measured the two-way speed of light, i.e., measuring the speed of light that travels from a source to another location and back to the source, and so there is a need for only one clock to measure the speed. Here, we show that it is possible, in principle, to measure the velocity of particles that travel at the speed of light without assuming a round-trip once we adopt a quantum mechanical description under two boundary conditions to the state of the quantum system followed by the two-state-vector formalism while assuming non-synchronized quantum clocks with unknown time dilation. We show that the weak value of velocity can be measured for a test particle that has a clock that is not synchronized with the clock of the quantum particle. Following the proposed setup, when the weak value of the velocity is known even without knowing the time states of the system, such a weak velocity is the two-way speed of light. Otherwise, one has to impose assumptions regarding the time states of the quantum clocks, which then give weak velocities that can be slower or even faster than the two-way speed of light. We further explore some fundamental implications of the setup. The proposed approach opens a new avenue toward measuring the velocities of quantum particles while overcoming relativistic issues regarding the synchronization of clocks.

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Antonio Vassallo, Pedro Naranjo

Thu Aug 01 2024 13:52:50 (1 day)

# 2.

arXiv:2407.21132v1 Announce Type: new Abstract: The paper discusses the possible implications of the relational framework of Pure Shape Dynamics for the metaphysics of time. The starting point of the analysis is an interpretation of shapes in ontic structural realist terms, which gives rise to the notion of self-subsisting structure. The relational version of a Newtonian-particle toy model is introduced and discussed as a concrete example.

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Ranyiliu Chen; Laura Mančinska; Jurij Volčič

Thu Aug 01 2024 08:00:00 (2 days)

# 3.

Nature Physics, Published online: 01 August 2024; doi:10.1038/s41567-024-02584-zQuantum correlations are strong enough that classical users can verify that a device produces quantum entangled states using only the outcomes of local measurements. This self-testing approach has now been extended to verifying quantum measurements.

from

Thu Aug 01 2024 03:02:48 (2 days)

# 4.

Huggett, Nick Through the Looking Glass and What Immanuel Found There. UNSPECIFIED.

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Nicolas Barros, Sergio Ciliberto, and Ludovic Bellon

Wed Jul 31 2024 18:00:00 (2 days)

# 5.

Author(s): Nicolas Barros, Sergio Ciliberto, and Ludovic Bellon

In a fully classical continuous system, the second law of thermodynamics can be violated locally while being preserved on average.

[Phys. Rev. Lett. 133, 057101] Published Wed Jul 31, 2024

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Emily Adlam

Wed Jul 31 2024 12:45:11 (2 days)

# 6.

arXiv:2407.20457v1 Announce Type: new Abstract: I suggest that the current situation in quantum field theory (QFT) provides some reason to question the universal validity of ontological reductionism. I argue that the renormalization group flow is reversible except at fixed points, which makes the relation between large and small distance scales quite symmetric in QFT, opening up at least the technical possibility of a non-reductionist approach to QFT. I suggest that some conceptual problems encountered within QFT may potentially be mitigated by moving to an alternative picture in which it is no longer the case that the large supervenes on the small. Finally, I explore some specific models in which a form of non-reductionism might be implemented, and consider the prospects for future development of these models.

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Emily Adlam

Wed Jul 31 2024 12:45:10 (2 days)

# 7.

arXiv:2407.20458v1 Announce Type: new Abstract: In this paper we seek to understand what current knowledge of entanglement entropies suggests about the appropriate way to interpret the covariant entropy bound. We first begin by arguing that just as in the classical case, a universal bound on the von Neumann entropy could have either an epistemic or ontological origin. We then consider several possible ways of explaining the bound as a consequence of features of the entanglement entropy. We discuss consider area laws in condensed matter and quantum field theory, arguing that they suggest an epistemic reading of the bound. We also discuss the ‘spacetime from entanglement’ programme, arguing that entanglement alone may not be able to full ground spacetime topology, but it could potentially play a role in determining the spacetime metric, in which case it would potentially support a more ontological reading of the bound.

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Eugene Y. S. Chua

Tue Jul 30 2024 12:24:27 (3 days)

# 8.

arXiv:2407.18948v1 Announce Type: new Abstract: Preparing general relativity for quantization in the Hamiltonian approach leads to the `problem of time,’ rendering the world fundamentally timeless. One proposed solution is the `thermal time hypothesis,’ which defines time in terms of states representing systems in thermal equilibrium. On this view, time is supposed to emerge thermodynamically even in a fundamentally timeless context. Here, I develop the worry that the thermal time hypothesis requires dynamics — and hence time — to get off the ground, thereby running into worries of circularity.

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Johannes Branahl

Tue Jul 30 2024 12:24:24 (3 days)

# 9.

arXiv:2403.20282v2 Announce Type: replace Abstract: We provide novel, metatheoretical arguments strengthening the position that the naturalness problem of the light Higgs mass is a pseudo-problem: No physics beyond the standard model of particle physics is needed to explain the small value of the Higgs boson. By evaluating previous successes of the guiding principle of technical naturalness, we restrict its applicability to non-fundamental phenomena in the realm of provisional theories within limited energy scales. In view of further breaches of autonomy of scales in apparently fundamental phenomena outside particle physics, the hierarchy problem of the Higgs mass is instead reinterpreted as an indication of the ontologically fundamental status of the Higgs boson. Applying the concept of Selective Realism justifies this seemingly contradictory attribution within the effective theories of the standard model of particle physics. Moreover, we argue that the ongoing naturalness debate about the Higgs mass is partly based on the adherence to the methodology of effective theories (often claimed to be universally applicable), for which there is no justification when dealing with presumably fundamental phenomena such as the Higgs mechanism, even if it is embedded into an effective theory.