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We propose in this paper a quantization scheme for real Klein-Gordon field in de Sitter spacetime. Our scheme is generally covariant with the help of vierbein, which is necessary usually for spinor field in curved spacetime. We first…

High Energy Physics - Theory · Physics 2023-09-06 Sze-Shiang Feng

In the geometry of quantum-mechanical processes, the time-varying curvature coefficient of a quantum evolution is specified by the magnitude squared of the covariant derivative of the tangent vector to the state vector. In particular, the…

Quantum Physics · Physics 2025-01-07 Carlo Cafaro , Leonardo Rossetti , Paul M. Alsing

Evolution of a universe with homogeneous extra dimensions is studied with the benefit of a well-chosen parameter space that provides a systematic, useful, and convenient way for analysis. In this model we find a natural evolution pattern…

Astrophysics · Physics 2009-11-10 Je-An Gu , W-Y. P. Hwang , Jr-Wei Tsai

We consider the spinless Pauli-Fierz Hamiltonian which describes a quantum system of non-relativistic identical particles coupled to the quantized electromagnetic field. We study the time evolution in a mean-field limit where the number $N$…

Mathematical Physics · Physics 2021-04-27 Nikolai Leopold , Peter Pickl

Some long standing issues concerning the quantum nature of the big bang are resolved in the context of homogeneous isotropic models with a scalar field. Specifically, the known results on the resolution of the big bang singularity in loop…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Abhay Ashtekar , Tomasz Pawlowski , Parampreet Singh

The real time non-equilibrium evolution of condensates in field theory requires an initial value problem specifying an initial quantum state or density matrix. Arbitrary specifications of the initial quantum state (pure or mixed) results in…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. Baacke , D. Boyanovsky , H. J. de Vega

The quantization of unimodular gravity in minisuperspace leads to a time evolution of states generated by the Hamiltonian, as in usual quantum mechanics. We revisit the analysis made in Ref. \cite{unruh}, extending it to phantom scalar…

General Relativity and Quantum Cosmology · Physics 2025-04-17 Júlio C. Fabris , Luiz Filipe Guimarães , Nelson Pinto-Neto , Mahamadou Hamani Daouda

There is a formal analogy between the evolution of the universe, when this is seen as a trajectory in the minisuperspace, and the worldline followed by a test particle in a curved spacetime. The analogy can be extended to the quantum realm,…

General Relativity and Quantum Cosmology · Physics 2018-12-31 Salvador J. Robles-Pérez

In the above mentioned paper by J. Dunkel and S. A. Trigger [Phys. Rev. {\bf A 71}, 052102, (2005)] a hypothesis has been pursued that the loss of information associated with the quantum evolution of pure states, quantified in terms of an…

Quantum Physics · Physics 2009-11-11 Piotr Garbaczewski

We study the time evolution of a wave function for the spatially flat Friedmann-Lemaitre-Robertson-Walker universe governed by the Wheeler-DeWitt equation in both analytical and numerical methods. We consider a Brown-Kuchar dust as a matter…

General Relativity and Quantum Cosmology · Physics 2015-12-14 Hideki Maeda

Unimodular quantum cosmology admits wavepacket solutions that evolve according to a kind of Schr\"odinger equation. Though this theory is equivalent to general relativity on the classical level, its canonical structure is different and the…

General Relativity and Quantum Cosmology · Physics 2022-12-07 Natascha Riahi

We present a compositional algebraic framework to describe the evolution of quantum fields in discretised spacetimes. We show how familiar notions from Relativity and quantum causality can be recovered in a purely order-theoretic way from…

Quantum Physics · Physics 2020-03-31 Stefano Gogioso , Maria E. Stasinou , Bob Coecke

A number of positive and null results on the time variation of fundamental constants have been reported. It is difficult to judge whether or not these claims are mutually consistent, since the observable quantities depend on several…

High Energy Physics - Phenomenology · Physics 2009-02-23 Thomas Dent , Steffen Stern , Christof Wetterich

We discuss the problem of the quantization and dynamic evolution of a scalar free field in the interior of a Schwarzschild black hole. A unitary approach to the dynamics of the quantized field is proposed: a time-dependent Hamiltonian…

General Relativity and Quantum Cosmology · Physics 2023-06-28 Pawel Gusin , Andrzej Radosz , Andy T. Augousti , Janos Polonyi , Oleg B. Zaslavskii , Romuald J. 'Sciborski

It was recently shown that Newtonian dynamics of macroscopic particles can be derived from unitary Schr\"odinger evolution under an assumption on the system-environment interaction, namely that the interaction Hamiltonian effectively…

Quantum Physics · Physics 2026-04-07 Alexey A. Kryukov

The Fock quantization of fields propagating in cosmological spacetimes is not uniquely determined because of several reasons. Apart from the ambiguity in the choice of the quantum representation of the canonical commutation relations, there…

General Relativity and Quantum Cosmology · Physics 2011-02-25 Jeronimo Cortez , Guillermo A. Mena Marugan , Javier Olmedo , Jose M. Velhinho

This paper investigates a new formalism to describe real time evolution of quantum systems at finite temperature. A time correlation function among subsystems will be derived which allows for a probabilistic interpretation. Our derivation…

High Energy Physics - Theory · Physics 2009-10-31 E. Mendel , M. Nest

Quantum theory of the free Maxwell field in Minkowski space is constructed using a representation in which the self dual connection is diagonal. Quantum states are now holomorphic functionals of self dual connections and a decomposition of…

High Energy Physics - Theory · Physics 2010-11-01 Abhay Ashtekar , Carlo Rovelli , Lee Smolin

We present a review of recent research on quantum entanglement, with special emphasis on entanglement between single atoms, processing of an encoded entanglement and its temporary evolution. Analysis based on the density matrix formalism…

Quantum Physics · Physics 2015-05-18 Zbigniew Ficek

In quantum theory it is possible to explain time, and dynamics, in terms of entanglement. This is the timeless approach to time, which assumes that the universe is in a stationary state, where two non-interacting subsystems, the clock and…

Quantum Physics · Physics 2017-02-22 Chiara Marletto , Vlatko Vedral