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PhilSci-Archive: No conditions. Results ordered -Date Deposited.

Fri Jan 27 2023 03:20:26 (1 day)

# 1.

Thebault, Karim P Y (2023) Big Bang Singularity Resolution In Quantum Cosmology. [Preprint]

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Thomas D. Galley, Flaminia Giacomini, John H. Selby

Thu Jan 26 2023 11:06:32 (1 day)

# 2.

When gravity is sourced by a quantum system, there is tension between its role as the mediator of a fundamental interaction, which is expected to acquire nonclassical features, and its role in determining the properties of spacetime, which is inherently classical. Fundamentally, this tension should result in breaking one of the fundamental principles of quantum theory or general relativity, but it is usually hard to assess which one without resorting to a specific model. Here, we answer this question in a theory-independent way using General Probabilistic Theories (GPTs). We consider the interactions of the gravitational field with a single matter system, and derive a no-go theorem showing that when gravity is classical at least one of the following assumptions needs to be violated: (i) Matter degrees of freedom are described by fully non-classical degrees of freedom; (ii) Interactions between matter degrees of freedom and the gravitational field are reversible; (iii) Matter degrees of freedom back-react on the gravitational field. We argue that this implies that theories of classical gravity and quantum matter must be fundamentally irreversible, as is the case in the recent model of Oppenheim et al. Conversely if we require that the interaction between quantum matter and the gravitational field are reversible, then the gravitational field must be non-classical.

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Pooya Farokhi, Tim Koslowski, Pedro Naranjo, Antonio Vassallo

Thu Jan 26 2023 11:06:24 (1 day)

# 3.

We provide the construction of a de Broglie-Bohm model of the $N$-body system within the framework of Pure Shape Dynamics. The equation of state of the curve in shape space is worked out, with the instantaneous shape being guided by a wave function. In order to get a better understanding of the dynamical system, we also give some numerical analysis for the 3-body case. Remarkably enough, our simulations typically show the attractor-driven behaviour of complexity, well known in the classical case, thereby providing further evidence for the claim that the arrow of complexity is the ultimate cause of the experienced arrow of time.

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Dominik Šafránek, Dario Rosa

Thu Jan 26 2023 11:06:17 (1 day)

# 4.

We present a method to estimate the mean value of any observable and its higher moments by measuring any other observable. This method is general and can be applied to any quantum system. In the case of estimating the mean energy of an isolated system, the estimate can be further improved by measuring the other observable at different times. Intuitively, this method uses interplay and correlations between the measured and the estimated observable, and the state of the system. We provide two bounds: one that is looser but analytically computable, and one that is tighter but requires solving a non-convex optimization problem. The method can be used to estimate expectation values and related quantities such as temperature and work in setups in which performing measurements in a highly entangled basis is difficult, finding use in state-of-the-art quantum simulators. As a demonstration, we show that in Heisenberg and Ising models of ten sites in the localized phase, performing two-qubit measurements excludes 97.5\% and 96.7\% of the possible range of energies, respectively, when estimating the ground state energy.

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Chao Xiao; Fei He; Quanqi Shi; Wenlong Liu; Anmin Tian; Ruilong Guo; Chao Yue; Xuzhi Zhou; Yong Wei; I. Jonathan Rae; Alexander W. Degeling; Vassilis Angelopoulos; Emmanuel V. Masongsong; Ji Liu; Qiugang Zong; Suiyan Fu; Zuyin Pu; Xiaoxin Zhang; Tieyan Wang; Huizi Wang; Zhao Zhang

Thu Jan 26 2023 08:00:00 (2 days)

# 5.

Nature Physics, Published online: 26 January 2023; doi:10.1038/s41567-022-01882-8

Lunar tides affect Earth’s oceans and its geomagnetic field. Multisatellite observations demonstrate that they also impact the plasmasphere.

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PhilSci-Archive: No conditions. Results ordered -Date Deposited.

Tue Jan 24 2023 03:26:11 (4 days)

# 6.

Broka, Chris A. (2023) Quantum Measurements and their Place in Nature. [Preprint]

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Ludovico Lami; Bartosz Regula

Mon Jan 23 2023 08:00:00 (5 days)

# 7.

Nature Physics, Published online: 23 January 2023; doi:10.1038/s41567-022-01873-9

A formal analysis of the physical limits of entanglement manipulation shows that it cannot be done reversibly, highlighting an important difference from thermodynamics.

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M. O. Brown; S. R. Muleady; W. J. Dworschack; R. J. Lewis-Swan; A. M. Rey; O. Romero-Isart; C. A. Regal

Mon Jan 23 2023 08:00:00 (5 days)

# 8.

Nature Physics, Published online: 23 January 2023; doi:10.1038/s41567-022-01890-8

A tomography protocol that exploits the control offered by optical tweezers allows the reconstruction of motional states of a single trapped atom. This has implications for the study of non-classical states of massive trapped and levitated particles.

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PhilSci-Archive: No conditions. Results ordered -Date Deposited.

Sun Jan 22 2023 13:35:37 (5 days)

# 9.

North, Jill and Baker, David John and Myrvold, Wayne C. and Ruetsche, Laura (2022) Author Meets Critics: Jill North, Physics, Structure and Reality. UNSPECIFIED.