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A modification of the covariant theory is proposed in which the self-energy of the system, corresponding to time-like degrees of freedom in the configuration space, preserves the classical law of change in quantum theory. As a result,…

General Relativity and Quantum Cosmology · Physics 2020-01-27 Natalia Gorobey , Alexander Lukyanenko

Several important dynamical systems are in $\mathbb{R}^2$, defined by the pair of differential equations $(x',y')=(f(x,y),g(x,y))$. A question of fundamental importance is how such systems might behave quantum mechanically. In developing…

Quantum Physics · Physics 2025-11-06 Andy Chia , Wai-Keong Mok , Leong-Chuan Kwek , Changsuk Noh

Standard quantum mechanics relies on two distinct dynamical principles: unitary evolution and collapse. A mathematically self-contained variational framework is presented that replaces this dualism with a single principle, in which…

Quantum Physics · Physics 2026-03-18 Lance H. Carter

Classical physics is reformulated as a constrained Hamiltonian system in the history phase space. Dynamics, i.e. the Euler-Lagrange equations, play the role of first-class constraints. This allows us to apply standard methods from the…

High Energy Physics - Theory · Physics 2007-05-23 T. A. Larsson

We show that the emergence of time evolution in an otherwise timeless nonrelativistic closed quantum system -- viewed as a poor man's model of generally covariant quantum theory -- can be understood from the perspective of the path integral…

General Relativity and Quantum Cosmology · Physics 2026-05-19 Juan Manuel Diaz , Alejandro Perez

Dynamical chaos has recently been shown to exist in the Gaussian approximation in quantum mechanics and in the self-consistent mean field approach to studying the dynamics of quantum fields. In this study, we first show that any variational…

Quantum Physics · Physics 2008-11-26 Fred Cooper , John Dawson , Salman Habib , Robert D. Ryne

In this letter, by establishing the Schr\"odinger equation of the optimization problem, the optimization problem is transformed into a constrained state quantum problem with the objective function as the potential energy. The mathematical…

Quantum Physics · Physics 2021-10-12 Peng Wang , Gang Xin , Yuwei Jiao

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 Dirac method of canonical quantization of theories with second class constraints has to be modified if the constraints depend on time explicitly. A solution of the problem was given by Gitman and Tyutin. In the present work we propose…

High Energy Physics - Theory · Physics 2008-11-26 S. A. Gadjiev , R. G. Jafarov

Scaling properties inherent in quantum dynamics have been studied for various systems in terms of acceleration, deceleration and time reversing. We show a scaling property of quantum dynamics on curved space-time where gravity plays an…

Quantum Physics · Physics 2025-08-08 Yuji Ando , Shumpei Masuda

Classical simulations of quantum computations are vital for the future development of this emerging technology. To this end, decision diagrams have been proposed as a complementary technique which frequently allows to tackle the inherent…

Quantum Physics · Physics 2023-01-11 Lukas Burgholzer , Hartwig Bauer , Robert Wille

The classical and quantum dynamics of simple time-reparametrization- invariant models containing two degrees of freedom are studied in detail. Elimination of one ``clock'' variable through the Hamiltonian constraint leads to a description…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Ian D. Lawrie , Richard J. Epp

In this paper, we propose and analyze a second-order time-stepping numerical scheme for the inhomogeneous backward fractional Feynman-Kac equation with nonsmooth initial data. The complex parameters and time-space coupled Riemann-Liouville…

Numerical Analysis · Mathematics 2024-08-13 Liyao Hao , Wenyi Tian

A general problem of quantum field theories is the fact that the free vacuum and the vacuum for an interacting theory belong to different, non-equivalent representations of the canonical (anti-)commutation relations. In the external field…

Mathematical Physics · Physics 2013-10-08 Dustin Lazarovici

In this paper we propose a time discretization of a system of two parabolic equations describing diffusion-driven atom rearrangement in crystalline matter. The equations express the balances of microforces and microenergy; the two phase…

Analysis of PDEs · Mathematics 2019-02-20 Pierluigi Colli , Gianni Gilardi , Pavel Krejčí , Paolo Podio-Guidugli , Jürgen Sprekels

We introduce the concept of strong quantum speedup. We prove that approximating the ground state energy of an instance of the time-independent Schr\"odinger equation, with $d$ degrees of freedom, $d$ large, enjoys strong exponential quantum…

Quantum Physics · Physics 2013-09-04 Anargyros Papageorgiou , Joseph F. Traub

Deutsch-Jozsa algorithm has been implemented via a quantum adiabatic evolution by S. Das et al. [Phys. Rev. A 65, 062310 (2002)]. This adiabatic algorithm gives rise to a quadratic speed up over classical algorithms. We show that a modified…

Quantum Physics · Physics 2009-11-11 Zhaohui Wei , Mingsheng Ying

This paper is the first of two papers devoted to formulation of quantum mechanics of a particle in a normal geodesic frame of reference in the general Riemannian space-time. Here canonical quantization of geodesic motion in the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 E. A. Tagirov

It has been recently reported that classical systems have speed limit for state evolution, although such a concept of speed limit had been considered to be unique to quantum systems. Owing to the speed limit for classical system, the lower…

Quantum Physics · Physics 2021-07-08 Akihisa Ichiki , Masayuki Ohzeki

We revisit the issue of time in quantum geometrodynamics and suggest a quantization procedure on the space of true dynamic variables. This procedure separates the issue of quantization from enforcing the constraints caused by the general…

General Relativity and Quantum Cosmology · Physics 2016-12-21 Warner A. Miller , Arkady Kheyfets