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We investigate quantum effects in the evolution of general systems. For studying such temporal quantum phenomena, it is paramount to have a rigorous concept and profound understanding of the classical dynamics in such a system in the first…

Quantum Physics · Physics 2020-06-02 J. Sperling , I. A. Walmsley

The dynamics of many open quantum systems are described by stochastic master equations. In the discrete-time case, we recall the structure of the derived quantum filter governing the evolution of the density operator conditioned to the…

Optimization and Control · Mathematics 2015-03-23 Pierre Six , Philippe Campagne-Ibarcq , Landry Bretheau , Benjamin Huard , Pierre Rouchon

We examine the logical structure of the emergence of classical stochasticity for a quantum system governed by a Pauli-type master equation. It is well-known that while such equations describe the evolution of probabilities, they do not…

Quantum Physics · Physics 2026-02-05 Xuan Du Trinh , Ismaël Septembre , Hai-Chau Nguyen

We investigate the role of a statistical complexity measure to assign equilibration in isolated quantum systems. While unitary dynamics preserve global purity, expectation values of observables often exhibit equilibration-like behavior,…

Quantum Physics · Physics 2025-08-14 Marcos G. Alpino , Tiago Debarba , Reinaldo O. Vianna , André T. Cesário

Quantum dynamics of coherent states is studied within quantum field theory using two complementary methods: by organizing the evolution as a Taylor series in elapsed time and by perturbative expansion in coupling within the…

High Energy Physics - Theory · Physics 2021-10-13 Lasha Berezhiani , Michael Zantedeschi

The logical structure of Quantum Mechanics (QM) and its relation to other fundamental principles of Nature has been for decades a subject of intensive research. In particular, the question whether the dynamical axiom of QM can be derived…

Quantum Physics · Physics 2009-10-20 Florian Hulpke , Uffe V. Poulsen , Anna Sanpera , Aditi Sen De , Ujjwal Sen , Maciej Lewenstein

We develop a dynamical framework for quantum measurement based on stochastic but unitary evolution in projective state space. Random Hamiltonians drawn from the Gaussian Unitary Ensemble generate stochastic unitary dynamics of the quantum…

Quantum Physics · Physics 2026-01-27 Alexey A. Kryukov

In complex systems, the interplay between nonlinear and stochastic dynamics, e.g., J. Monod's necessity and chance, gives rise to an evolutionary process in Darwinian sense, in terms of discrete jumps among attractors, with punctuated…

Adaptation and Self-Organizing Systems · Physics 2013-03-18 Hong Qian

Without wasting time and effort on philosophical justifications and implications, we write down the conditions for the Hamiltonian of a quantum system for rendering it mathematically equivalent to a deterministic system. These are the…

Quantum Physics · Physics 2020-06-09 Gerard t Hooft

Quantum particles and classical particles are described in a common setting of classical statistical physics. The property of a particle being "classical" or "quantum" ceases to be a basic conceptual difference. The dynamics differs,…

Quantum Physics · Physics 2015-05-13 C. Wetterich

Each scheme of state reconstruction comes down to parametrize the state of a quantum system by expectation values or probabilities directly measurable in an experiment. It is argued that the time evolution of these quantities provides an…

Quantum Physics · Physics 2014-11-18 Stefan Weigert

A quantum-mechanical system comes naturally equipped with a convex space: each (Hermitian) operator has a (real) expectation value, and the expectation value of the square any Hermitian operator must be non-negative. This space is of…

High Energy Physics - Lattice · Physics 2025-02-05 Scott Lawrence

We investigate the transition from quantum to classical mechanics using a one-dimensional free particle model. In the classical analysis, we consider the initial positions and velocities of the particle drawn from Gaussian distributions.…

Quantum Physics · Physics 2024-05-30 E. Aldo Arroyo

The time dependence of one-dimensional quantum mechanical probability densities is presented when the potential in which a particle moves is suddenly changed, called a quench. Quantum quenches are mainly addressed but a comparison with…

Quantum Physics · Physics 2024-06-18 K. Schönhammer

We analyze the issue of dynamical evolution and time in quantum cosmology. We emphasize the problem of choice of phase space variables that can play the role of a time parameter in such a way that for expectation values of quantum operators…

General Relativity and Quantum Cosmology · Physics 2021-07-05 Alexander Yu. Kamenshchik , Jeinny Nallely Perez Rodriguez , Tereza Vardanyan

We develop a master equation formalism to describe the evolution of the average density matrix of a closed quantum system driven by a stochastic Hamiltonian. The average over random processes generally results in decoherence effects in…

Quantum Physics · Physics 2011-11-30 Li Yu , Daniel F. V. James

The claim that there is an inconsistency of quantum-classical dynamics [1] is investigated. We point out that a consistent formulation of quantum and classical dynamics which can be used to describe quantum measurement processes is already…

Quantum Physics · Physics 2007-05-23 E. C. G. Sudarshan

The theories of stochastic quantum mechanics and stochastic electrodynamics bring to light important aspects of the quantum dynamics that are concealed in the standard formalism. Here we take further previous work regarding the connection…

Quantum Physics · Physics 2021-04-28 A. M. Cetto , L. de la Peña , A. Valdés-Hernández

We compare two proposals for the dynamical entropy of quantum deterministic systems (CNT and AFL) by studying their extensions to classical stochastic systems. We show that the natural measurement procedure leads to a simple explicit…

Mathematical Physics · Physics 2009-11-07 Mark Fannes , Bart Haegeman

We study the dynamics of states perturbatively expanded about a harmonic system of loop quantum cosmology, exhibiting a bounce. In particular, the evolution equations for the first and second order moments of the system are analyzed. These…

General Relativity and Quantum Cosmology · Physics 2011-01-20 Martin Bojowald , David Mulryne , William Nelson , Reza Tavakol