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Related papers: The problem with `The Problem of Time'

200 papers

We investigate the origin of the arrow of time in quantum mechanics in the context of quantum cosmology. The ``Copenhagen'' quantum mechanics of measured subsystems incorporates a fundamental arrow of time. Extending discussions of…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Murray Gell-Mann , James B. Hartle

This paper is a continuation of the papers [gr-qc/9409010, gr-qc/9505034, gr-qc/9603022, gr-qc/9609035] and is devoted to the riddle of the origin of the arrow of time. The problem of time orientation reduces to that of the difference…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Vladimir S. Mashkevich

We investigate quantum correlations in time in different approaches. We assume that temporal correlations should be treated in an even-handed manner with spatial correlations. We compare the pseudo-density matrix formalism with several…

Quantum Physics · Physics 2020-12-23 Tian Zhang , Oscar Dahlsten , Vlatko Vedral

One of the most fundamental open problems in physics is the unification of general relativity and quantum theory to a theory of quantum gravity. An aspect that might become relevant in such a theory is that the dynamical nature of causal…

Quantum Physics · Physics 2022-03-14 Veronika Baumann , Marius Krumm , Philippe Allard Guérin , Časlav Brukner

The "problem of time" in canonical quantum gravity refers to the difficulties involved in defining a Hilbert space structure on states -- and local observables on this Hilbert space -- for a theory in which the spacetime metric is treated…

General Relativity and Quantum Cosmology · Physics 2009-12-30 Robert M. Wald

Scientists continue to wrestle with the enigma of time. Is time a dynamic or a fundamental property of spacetime? Why does it have an arrow pointing from past to future? Why are physical laws time-symmetric in a universe with broken…

General Relativity and Quantum Cosmology · Physics 2009-09-15 L. Mersini-Houghton

We have studied various classical solutions in $R^2$ cosmology. Especially we have obtained general classical solutions in pure $R^2$\ cosmology. Even in the quantum theory, we can solve the Wheeler-DeWitt equation in pure $R^2$\ cosmology…

General Relativity and Quantum Cosmology · Physics 2009-10-28 M. Kenmoku , K. Otsuki , K. Shigemoto , K. Uehara

The problem of time evolution in quantum cosmology is studied in the context of a dust-filled, spatially flat Friedmann-Robertson-Walker universe. In this model, two versions of the commonly-adopted notion of internal time can be…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Ian D. Lawrie

We propose a solution to the problem of time for systems with a single global Hamiltonian constraint. Our solution stems from the observation that, for these theories, conventional gauge theory methods fail to capture the full classical…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Sean Gryb , Karim Thebault

Conceptual problems regarding the arrow of time in classical physics, quantum physics, cosmology, and quantum gravity are discussed. Particular attention is paid to the dynamical role of the quantum indeterminism, and to various concepts of…

General Relativity and Quantum Cosmology · Physics 2012-07-30 H. D. Zeh

It is often said that in general relativity time does not exist. This is because the Einstein equations generate motion in time that is a symmetry of the theory, not true time evolution. In quantum gravity, the timelessness of general…

General Relativity and Quantum Cosmology · Physics 2009-09-11 Fotini Markopoulou

Different approaches to quantum gravity, such as loop quantum cosmology and group field theory, predict the resolution of the initial cosmological singularity via a bounce: a regular spacetime region that connects the expanding branch of…

General Relativity and Quantum Cosmology · Physics 2024-11-01 Marco de Cesare

This thesis addresses two major problems in the philosophy of physics. The first is how to identify the minimal physical content of a theory; that is, what features of a theory are truly needed to make predictions, and what can be removed…

History and Philosophy of Physics · Physics 2025-09-19 Sean Gryb

The relationship between 'information' and 'time' is explored in order to look for a 'solution' to the 'Problem of Time'. 'Time' is found to be the result of the conversion of energy into 'information'. The 'time' number or label we assign…

Quantum Physics · Physics 2007-05-23 Scott M. Hitchcock

We conduct a case study analysis of a proposal for the emergence of time based upon the approximate derivation of three grades of temporal structure within an explicit quantum cosmological model which obeys a Wheeler-DeWitt type equation…

General Relativity and Quantum Cosmology · Physics 2023-10-18 Nick Huggett , Karim P. Y. Thébault

Quantum cosmology offers a unique stage to address questions of time related to its underlying (and perhaps truly quantum dynamical) meaning as well as its origin. Some of these issues can be analyzed with a general scheme of quantum…

General Relativity and Quantum Cosmology · Physics 2012-07-25 Martin Bojowald

Several novel approaches have been proposed to resolve the problem of time by relating it to change. We argue using quantum information theory that the Hamiltonian constraint in quantum gravity cannot probe change, so it cannot be used to…

General Relativity and Quantum Cosmology · Physics 2022-02-07 Salman Sajad Wani , James Q. Quach , Mir Faizal , Sebastian Bahamonde , Behnam Pourhassan

I address the question whether the origin of the observed arrow of time can be derived from quantum cosmology. After a general discussion of entropy in cosmology and some numerical estimates, I give a brief introduction into quantum…

General Relativity and Quantum Cosmology · Physics 2012-07-27 Claus Kiefer

The nature of time as emergent for a system by separating it from its environment has been put forward by Page and Wootters [D. N. Page and W. K. Wootters, Phys. Rev. D 27, 2885 (1983)] in a quantum mechanical setting neglecting interaction…

Quantum Physics · Physics 2023-09-12 Sebastian Gemsheim , Jan M. Rost

Uncovering the origin of the arrow of time remains a fundamental scientific challenge. Within the framework of statistical physics, this problem was inextricably associated with the second law of thermodynamics, which declares that entropy…

Quantum Physics · Physics 2018-02-27 G. B. Lesovik , I. A. Sadovskyy , M. V. Suslov , A. V. Lebedev , V. M. Vinokur
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