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The semiclassical treatment of the two-dimensional harmonic oscillator provides an instructive example of the relation between classical motion and the quantum mechanical energy spectrum. We extend previous work on the anisotropic…

Quantum Physics · Physics 2007-05-23 Roland Doll , Gert-Ludwig Ingold

In the frames of classical mechanics the generalized Langevin equation is derived for an arbitrary mechanical subsystem coupled to the harmonic bath of a solid. A time-acting temperature operator is introduced for the quantum Klein-Kramers…

Quantum Physics · Physics 2021-05-17 Roumen Tsekov

Starting from the Schr\"odinger-equation of a composite system, we derive unified dynamics of a classical harmonic system coupled to an arbitrary quantized system. The classical subsystem is described by random phase-space coordinates…

Quantum Physics · Physics 2007-05-23 Lajos Diosi

Extension of Feynman's path integral to quantum mechanics of noncommuting spatial coordinates is considered. The corresponding formalism for noncommutative classical dynamics related to quadratic Lagrangians (Hamiltonians) is formulated.…

High Energy Physics - Theory · Physics 2009-11-10 Branko Dragovich , Zoran Rakic

We show how to write a set of brackets for the Langevin equation, describing the dissipative motion of a classical particle, subject to external random forces. The method does not rely on an action principle, and is based solely on the…

High Energy Physics - Theory · Physics 2009-11-10 Giuseppe Bimonte , Giampiero Esposito , Giuseppe Marmo , Cosimo Stornaiolo

We point out that when a quadratic type Li\'enard equation is suitably interpreted shows branching due to the double valuedness of the governing Hamiltonian. Under certain approximation of the guiding coupling constant we derive its quantum…

Quantum Physics · Physics 2018-02-13 Bijan Bagchi , Dibyendu Ghosh , Tarun R. Tummuru

We introduce a new class of quantum models with time-dependent Hamiltonians of a special scaling form. By using a couple of time-dependent unitary transformations, the time evolution of these models is expressed in terms of related systems…

Quantum Physics · Physics 2009-11-07 L. Samaj

We analyze the microscopic model of quantum Brownian motion, describing a Brownian particle interacting with a bosonic bath through a coupling which is linear in the creation and annihilation operators of the bath, but may be a nonlinear…

Quantum Gases · Physics 2015-04-17 Pietro Massignan , Aniello Lampo , Jan Wehr , Maciej Lewenstein

It has long been known that there exists a coordinate transformation which exactly maps the quantum free particle to the quantum harmonic oscillator. Here we extend this result by reformulating it as a unitary operation followed by a time…

Quantum Physics · Physics 2022-11-23 Gerard McCaul , Denys I. Bondar

In this paper we derive an exact master equation for two coupled quantum harmonic oscillators interacting via bilinear coupling with a common environment at arbitrary temperature made up of many harmonic oscillators with a general spectral…

Quantum Physics · Physics 2008-11-26 Chung-Hsien Chou , Ting Yu , B. L. Hu

In the framework of the Lindblad theory for open quantum systems, a master equation for the quantum harmonic oscillator interacting with a dissipative environment, in particular with a thermal bath, is derived for the case when the…

Quantum Physics · Physics 2009-11-13 A. Isar , A. Sandulescu , W. Scheid

With this work we elaborate on the physics of quantum noise in thermal equilibrium and in stationary non-equilibrium. Starting out from the celebrated quantum fluctuation-dissipation theorem we discuss some important consequences that must…

Quantum Physics · Physics 2007-05-23 Peter Hänggi , Gert-Ludwig Ingold

The dynamics of classical and quantum systems which are driven by a high frequency ($\omega$) field is investigated. For classical systems the motion is separated into a slow part and a fast part. The motion for the slow part is computed…

Chaotic Dynamics · Physics 2009-11-10 Saar Rahav , Ido Gilary , Shmuel Fishman

Dissipative forces are ubiquitous and thus constitute an essential part of realistic physical theories. However, quantization of dissipation has remained an open challenge for nearly a century. We construct a quantum counterpart of…

Quantum Physics · Physics 2016-04-21 Denys I. Bondar , Renan Cabrera , Andre Campos , Shaul Mukamel , Herschel A. Rabitz

We observe that a wide class of higher-derivative systems admits a bounded integral of motion that ensures the classical stability of dynamics, while the canonical energy is unbounded. We use the concept of a Lagrange anchor to demonstrate…

High Energy Physics - Theory · Physics 2015-06-22 D. S. Kaparulin , S. L. Lyakhovich , A. A. Sharapov

All measurable predictions of classical mechanics can be reproduced from a quantum-like interpretation of a nonlinear Schrodinger equation. The key observation leading to classical physics is the fact that a wave function that satisfies a…

Quantum Physics · Physics 2014-11-18 H. Nikolic

In this work we study an inverse dynamical problem for a bipartite quantum system governed by the time local master equation: to find the class of generators which give rise to a certain time evolution with the constraint of fixed reduced…

Quantum Physics · Physics 2020-11-19 Giuseppe Baio , Dariusz Chruscinski , Antonino Messina

This manuscript aims to illustrate a quantum-classical dissipative theory (suited to be converted to effective algorithms for numerical simulations) within the long-term project of studying molecular processes in the brain. Other…

Neurons and Cognition · Quantitative Biology 2025-03-04 Alessandro Sergi , Antonino Messina , Rosalba Saija , Gabriella Martino , Maria Teresa Caccamo , Min-Fang Kuo , Michael A. Nitsche

We study the classical mechanics and dynamics of particles that retains some memory of quantum statistics. Our work builds on earlier work on the statistical mechanics and thermodynamics of such particles. Starting from the effective…

Quantum Physics · Physics 2025-11-21 Varsha Subramanyan , T. H. Hansson , Smitha Vishveshwara

We prove a theorem showing that quantum mechanics is not directly a stochastic process characterizing Brownian motion but rather its square root. This implies that a complex-valued stochastic process is involved. Schr\"odinger equation is…

Mathematical Physics · Physics 2012-01-31 Marco Frasca