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Related papers: The problem of time in quantum cosmology

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We study the classical and quantum cosmology of a $(4+d)$-dimensional spacetime minimally coupled to a scalar field and present exact solutions for the resulting field equations for the case where the universe is spatially flat. These…

High Energy Physics - Theory · Physics 2009-11-10 S. Jalalzadeh , F. Ahmadi , H. R. Sepangi

In previous works, we showed that both time and space can emerge from entanglement within a globally constrained quantum Universe, with no background coordinates. By extending the Page and Wootters quantum time formalism to include both…

General Relativity and Quantum Cosmology · Physics 2025-09-30 Tommaso Favalli

The anisotropic Bianchi I cosmological model coupled with perfect fluid is quantized in the minisuperspace. The perfect fluid is described by using the Schutz formalism which allows to attribute dynamical degrees of freedom to matter. A…

General Relativity and Quantum Cosmology · Physics 2015-06-25 F. G. Alvarenga , A. B. Batista , J. C. Fabris , S. V. B. Gonçalves

We offer a new proposal for cosmic singularity resolution based upon a quantum cosmology with a unitary bounce. This proposal is illustrated via a novel quantization of a mini-superspace model in which there can be superpositions of the…

General Relativity and Quantum Cosmology · Physics 2018-12-17 Sean Gryb , Karim P. Y. Thébault

Quantum gravity (or quantum spacetime) is to unify general relativity and quantum mechanics into a single theoretical framework and presented as the most important open puzzle in fundamental physics. The development of a microscopic theory…

General Physics · Physics 2025-10-24 Su-Peng Kou

We consider the gravity interacting with matter scalar fields and quantized in the minisuperspace approach in which the wave functional is described by the Wheeler-DeWitt equations (WdW). Assuming the domination of the homogeneous and…

High Energy Physics - Theory · Physics 2016-04-08 Alexander A. Andrianov , Oleg O. Novikov , Chen Lan

The absolute/relative debate on the nature of space and time is ongoing for thousands of years. Here we attempt to investigate space and time from the information theoretic point of view to understand spatial and temporal correlations under…

Quantum Physics · Physics 2021-01-22 Tian Zhang

We study the classical and quantum models of a flat Friedmann-Robertson-Walker (FRW) space-time, coupled to a perfect fluid, in the context of the consensus and a gauge-fixed Lagrangian frameworks. It is shown that, either in the usual or…

General Relativity and Quantum Cosmology · Physics 2015-03-19 Babak Vakili

The Wheeler-DeWitt equation in quantum gravity is timeless in character. In order to discuss quantum to classical transition of the universe, one uses a time prescription in quantum gravity to obtain a time contained description starting…

General Relativity and Quantum Cosmology · Physics 2009-10-31 S. Biswas , A. Shaw , B. Modak

We consider a simple cosmological model consisting of an empty Bianchi I Universe, whose Hamiltonian we deparametrise to provide a natural clock variable. The model thus effectively describes an isotropic universe with an induced clock…

General Relativity and Quantum Cosmology · Physics 2022-01-26 Przemysław Małkiewicz , Patrick Peter , S. D. P. Vitenti

We consider a global quantum system (the "Universe") satisfying a double constraint, both on total energy and total momentum. Generalizing the Page and Wootters quantum clock formalism, we provide a model of 3+1 dimensional,…

Quantum Physics · Physics 2022-11-10 Tommaso Favalli , Augusto Smerzi

The space discreteness hypothesis asserts that the nature of space at short distances is radically different from that at large distances. Based on the Bronstein inequality, here, we use a totally disconnected topological space…

Quantum Physics · Physics 2026-05-28 W. A. Zúñiga-Galindo

We present the Hamiltonian formulation of a relativistic point-particle coupled to Einstein gravity and its canonical quantization \`a la Wheeler-DeWitt. In the resulting quantum theory, the wave functional is a function of the particle…

General Relativity and Quantum Cosmology · Physics 2021-03-15 Ward Struyve

We discuss the quantization in the minisuperspace for the generalized fourth-order teleparallel cosmological theory known as $f\left( T,B\right) $. Specifically we focus on the case where the theory is linear on the torsion scalar, in that…

General Relativity and Quantum Cosmology · Physics 2021-06-08 Andronikos Paliathanasis

In the present work, we study the quantum cosmology description of a Friedmann-Robertson-Walker model in the presence of a stiff matter perfect fluid and a negative cosmological constant. We work in the Schutz's variational formalism and…

General Relativity and Quantum Cosmology · Physics 2015-05-28 G. Oliveira-Neto , G. A. Monerat , E. V. Corrêa Silva , C. Neves , L. G. Ferreira

Even though quantum systems in energy eigenstates do not evolve in time, they can exhibit correlations between internal degrees of freedom in such a way that one of the internal degrees of freedom behaves like a clock variable, and thereby…

General Relativity and Quantum Cosmology · Physics 2015-09-30 Serge Massar , Philippe Spindel , Andrés F. Varón , Christof Wunderlich

Space-time is one of the most essential, yet most mysterious concepts in physics. In quantum mechanics it is common to understand time as a marker of instances of evolution and define states around all the space but at one time; while in…

Quantum Physics · Physics 2020-12-01 Tian Zhang , Oscar Dahlsten , Vlatko Vedral

We describe a link between the cosmological constant problem and the problem of time in quantum gravity. This arises by examining the relationship between the cosmological constant and vacuum energy in light of non-perturbative formulations…

General Relativity and Quantum Cosmology · Physics 2010-03-12 Viqar Husain

In this work, resolutions will be given for commonly stated problems associated with a model that assumes that space and time are discretized (i.e., atomized). This model is in contrast to the continuous space-time model that is used in all…

Classical Physics · Physics 2018-10-10 David T Crouse

We give an explicit, rigorous framework for calculating quantum probabilities in a model theory of quantum gravity. Specifically, we construct the decoherence functional for the Wheeler-DeWitt quantization of a flat…

General Relativity and Quantum Cosmology · Physics 2011-01-20 David A. Craig , Parampreet Singh