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Related papers: Classical Systems in Quantum Mechanics

200 papers

In complete analogy with the classical situation (which is briefly reviewed) it is possible to define bi-Hamiltonian descriptions for Quantum systems. We also analyze compatible Hermitian structures in full analogy with compatible Poisson…

Mathematical Physics · Physics 2009-11-11 G. Marmo , G. Scolarici , A. Simoni , F. Ventriglia

Decoherence of a quantum system (which then starts to display classical features) results from the interaction of the system with the environment, and is well described in the framework of the theory of continuous quantum measurements…

Quantum Physics · Physics 2010-12-17 Michael B. Mensky

We investigate modifications of quantum mechanics (QM) that replace the unitary group in a finite dimensional Hilbert space with a finite group and determine the minimal sequence of subgroups necessary to approximate QM arbitrarily closely…

High Energy Physics - Theory · Physics 2020-01-30 T. Banks

We sketch a quantum mechanical framework for the universe as a whole. Within that framework we propose a program for describing the ultimate origin in quantum cosmology of the quasiclassical domain of familiar experience and for…

General Relativity and Quantum Cosmology · Physics 2018-03-14 Murray Gell-Mann , James B. Hartle

A pedagogical introduction is given to the quantum mechanics of closed systems, most generally the universe as a whole. Quantum mechanics aims at predicting the probabilities of alternative coarse-grained time histories of a closed system.…

General Relativity and Quantum Cosmology · Physics 2014-01-15 James B. Hartle

Based on the concept of ensemble, it is proved in the manuscript that the probability amplitude function can also been used to describe the classical statistical system. The motion equations of probability amplitude functions of classical…

Classical Physics · Physics 2007-05-23 Xiaochun Mei

The question about the existence of so-called ``hidden'' variables in quantum mechanics and the perception of the completeness of quantum mechanics are two sides of the same coin. Quantum analytical mechanics constitutes a completion of…

Quantum Physics · Physics 2026-05-01 Wolfgang Paul

Based on a number of experimentally verified physical observations, it is argued that the standard principles of quantum mechanics should be applied to the Universe as a whole. Thus, a paradigm is proposed in which the entire Universe is…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. S. Eakins

A suitable unified statistical formulation of quantum and classical mechanics in a *-algebraic setting leads us to conclude that information itself is noncommutative in quantum mechanics. Specifically we refer here to an observer's…

Quantum Physics · Physics 2018-07-02 Rocco Duvenhage

Classical and quantum physics represent two distinct theories; however, quantum physics is regarded as the more fundamental of the two. It is posited that classical mechanics should arise from quantum mechanics under certain limiting…

Quantum Physics · Physics 2026-01-21 Abdul Rahaman Shaikh , Tabish Qureshi

For a wide set of quantum systems it is demonstrated that the quantum regime can be considered as the transient phase while the final classical statistical regime is a permanent state. A basis where exact matrix decoherence appears for…

Quantum Physics · Physics 2009-11-06 Mario Castagnino , Roberto Laura

Quantum computing is concerned with computer technology based on the principles of quantum mechanics, with operations performed at the quantum level. Quantum computational models make it possible to analyze the resources required for…

Formal Languages and Automata Theory · Computer Science 2019-01-24 Amandeep Singh Bhatia , Ajay Kumar

We present a description of the measurement process based on the parametric representation with environmental coherent states. This representation is specifically tailored for studying quantum systems whose environment needs being…

Quantum Physics · Physics 2015-09-30 Pietro Liuzzo-Scorpo , Alessandro Cuccoli , Paola Verrucchi

We define syntax and semantics of quantum circuits, allowing measurement gates and classical channels. We define circuit-based quantum algorithms and prove that, semantically, any such algorithm is equivalent to a single measurement that…

Quantum Physics · Physics 2021-07-20 Yuri Gurevich , Andreas Blass

Quantum correlations can be naturally formulated in a classical statistical system of infinitely many degrees of freedom. This realizes the underlying non-commutative structure in a classical statistical setting. We argue that the quantum…

Quantum Physics · Physics 2015-06-26 C. Wetterich

This note derives the stochastic differential equations and partial differential equation of general hybrid quantum--classical dynamics from the theory of continuous measurement and general (non-Markovian) feedback. The advantage of this…

Quantum Physics · Physics 2024-09-18 Antoine Tilloy

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

In the classical world one can construct two identical systems which have identical behavior and give identical measurement results. We show this to be impossible in the quantum domain. We prove that after the same quantum measurement two…

Quantum Physics · Physics 2017-01-10 Denis Sych , Gerd Leuchs

The classical limit of quantum mechanics is discussed for closed quantum systems in terms of observational aspects. Initially, the failure of the limit h->0 is explicitly demonstrated in a model of two quantum mechanically interacting…

Quantum Physics · Physics 2008-09-29 R. M. Angelo

The scope of this work is to provide a self-contained introduction to a selection of basic theoretical aspects in the modeling and control of quantum mechanical systems, as well as a brief survey on the main approaches to control synthesis.…

Quantum Physics · Physics 2012-10-29 Claudio Altafini , Francesco Ticozzi