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We investigate the quantum evolution of the metric operators for Bianchi-Type I model universes in the Heisenberg picture in order to remove the need to consider the wave function of the universe and interpret its "spin" variables. The…

General Relativity and Quantum Cosmology · Physics 2008-11-26 R. B. Mann , G. L. Murphy

In a wide range of quantum gravity theories, quasiclassical geometries, which are solutions to the Einstein field equations approximately, are described by "coherent states." Here we propose a Hamiltonian formalism for gravitational…

General Relativity and Quantum Cosmology · Physics 2025-12-01 Sijia Wang , Achintya Sajeendran , Dong-han Yeom , Robert B. Mann , Joshua Foo

Deterministic dynamical models are discussed which can be described in quantum mechanical terms. -- In particular, a local quantum field theory is presented which is a supersymmetric classical model. The Hilbert space approach of Koopman…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Hans-Thomas Elze

We have previously presented a version of the Weak Equivalence Principle for a quantum particle as an exact analog of the classical case, based on the Heisenberg picture analysis of free particle motion. Here, we take that to a full…

General Relativity and Quantum Cosmology · Physics 2025-06-17 Otto C. W. Kong

We explore the quantization of classical models with position-dependent mass (PDM) terms constrained to a bounded interval in the canonical position. This is achieved through the Weyl-Heisenberg covariant integral quantization by properly…

Quantum Physics · Physics 2020-12-30 Jean-Pierre Gazeau , Véronique Hussin , James Moran , Kevin Zelaya

Viewed as approximations to quantum mechanics, classical evolutions can violate the positive-semidefiniteness of the density matrix. The nature of this violation suggests a classification of dynamical systems based on classical-quantum…

Quantum Physics · Physics 2009-11-06 Salman Habib , Kurt Jacobs , Hideo Mabuchi , Robert Ryne , Kosuke Shizume , Bala Sundaram

The semi-classical approach to the quantum geometrodynamical model is used for the description of the properties of the universe on extremely small spacetime scales. Quantum theory for a homogeneous, isotropic and closed universe is…

General Relativity and Quantum Cosmology · Physics 2009-10-21 V. E. Kuzmichev , V. V. Kuzmichev

We are interested in this paper with the connection between the dynamics of a model related to Nuclear Magnetic Resonance (NMR) in Quantum Field Theory (QFT) with its classical counterpart known as the Maxwell-Bloch equations. The model in…

Analysis of PDEs · Mathematics 2018-03-06 Laurent Amour , Lisette Jager , Jean Nourrigat

We propose that the constants of Nature we observe (which appear as parameters in the classical action) are quantum observables in a kinematical Hilbert space. When all of these observables commute, our proposal differs little from the…

General Relativity and Quantum Cosmology · Physics 2019-01-09 John D. Barrow , Joao Magueijo

We develop a generic method to compute the dynamics induced by quenches in completely connected quantum systems. These models are expected to provide a mean-field description at least of the short time dynamics of finite dimensional system.…

Quantum Gases · Physics 2014-05-13 Bruno Sciolla , Giulio Biroli

A recent development of the studies on classical and quasi-classical properties of supersymmetric quantum mechanics in Witten's version is reviewed. First, classical mechanics of a supersymmetric system is considered. Solutions of the…

High Energy Physics - Theory · Physics 2016-09-06 Georg Junker , Stephan Matthiesen , Akira Inomata

The numerical treatment of quantum mechanics in the semi-classical regime is known to be computationally demanding, due to the highly oscillatory behaviour of the wave function and its large spatial extension. A recently proposed…

Quantum Physics · Physics 2024-02-13 Christoph Nölle

In this work we construct an effective four-dimensional model by compactifying a ten-dimensional theory of gravity coupled with a real scalar dilaton field on a time-dependent torus. The corresponding action in four dimensions is similar to…

General Relativity and Quantum Cosmology · Physics 2018-04-03 J. Socorro , L. Toledo Sesma , Luis O. Pimentel

We investigate how the quantum dynamics of gravitational models depends on the internal clock employed in quantisation. Our previous result on the quantum Friedmann-Lemaitre model demonstrates that almost all physical predictions from the…

General Relativity and Quantum Cosmology · Physics 2017-09-01 Przemyslaw Malkiewicz

We demonstrate that there exists a large class of action functionals of the scalar curvature and of the Gauss-Bonnet invariant which are able to relax dynamically a large cosmological constant (CC), whatever it be its starting value in the…

High Energy Physics - Theory · Physics 2011-05-19 Florian Bauer , Joan Sola , Hrvoje Stefancic

Making use of the $1 + 3$ covariant formalism, we show explicitly the effect that nonmetricity has on the dynamics of the universe. Then, using the Dynamical System Approach, we analyze the evolution of Bianchi type-I cosmologies within the…

General Relativity and Quantum Cosmology · Physics 2022-11-16 Fabrizio Esposito , Sante Carloni , Stefano Vignolo

We propose an approach to the study of open quantum systems based on a parametric representation of the principal system. The representation is obtained introducing generalized coherent states for the environment, and is such that the…

Quantum Physics · Physics 2013-12-12 Dario Calvani , Alessandro Cuccoli , Nikitas Gidopoulos , Paola Verrucchi

We consider a semi-classical approximation to the dynamics of a point particle in a noncommutative space. In this approximation, the noncommutativity of space coordinates is described by a Poisson bracket. For linear Poisson brackets, the…

High Energy Physics - Theory · Physics 2024-05-24 Vladislav Kupriyanov , Maxim Kurkov , Alexey Sharapov

A simple position probability density formulation is presented for the motion of a particle in a spherically symmetric potential. The approach provides an alternative to Newtonian methods for presentation in an elementary course, and…

Physics Education · Physics 2007-05-23 Lorenzo J. Curtis , David G. Ellis

Quantum mechanics can be formulated in terms of phase-space functions, according to Wigner's approach. A generalization of this approach consists in replacing the density operators of the standard formulation with suitable functions, the…

Mathematical Physics · Physics 2015-06-17 Paolo Aniello
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