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Related papers: Classical states, quantum field measurement

200 papers

A mathematically well-defined, manifestly covariant theory of classical and quantum field is given, based on Euclidean Poisson algebras and a generalization of the Ehrenfest equation, which implies the stationary action principle. The…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Arnold Neumaier

A class of interacting classical random fields is constructed using deformed *-algebras of creation and annihilation operators. The fields constructed are classical random field versions of "Lie fields". A vacuum vector is used to construct…

Quantum Physics · Physics 2008-10-15 Peter Morgan

Quantum mechanics for a four-state-system is derived from classical statistics. Entanglement, interference, the difference between identical fermions or bosons and the unitary time evolution find an interpretation within a classical…

Quantum Physics · Physics 2009-10-06 C. Wetterich

A novel theory of hybrid quantum-classical systems is developed, utilizing the mathematical framework of constrained dynamical systems on the quantum-classical phase space. Both, the quantum and the classical descriptions of the respective…

Quantum Physics · Physics 2015-06-16 N. Buric , D. B. Popovic , S. Prvanovic , M. Radonjic

We show that classicality emerges during quantum phase transitions due to parametric interactions without coupling to environments. The Wigner functions are explicitly calculated for the Gaussian vacuum, number, and thermal states of a free…

High Energy Physics - Phenomenology · Physics 2009-10-31 Sang Pyo Kim , Chul H. Lee

Consistent dynamics which couples classical and quantum degrees of freedom exists, provided it is stochastic. This dynamics is linear in the hybrid state, completely positive and trace preserving. One application of this is to study the…

Quantum Physics · Physics 2023-01-04 Jonathan Oppenheim , Carlo Sparaciari , Barbara Šoda , Zachary Weller-Davies

We show that the dynamics of a quantum system can be represented by the dynamics of an underlying classical systems obeying the Hamilton equations of motion. This is achieved by transforming the phase space of dimension $2n$ into a Hilbert…

Statistical Mechanics · Physics 2023-08-02 Mário j. de Oliveira

A non--commutative analogue of the classical differential forms is constructed on the phase--space of an arbitrary quantum system. The non--commutative forms are universal and are related to the quantum mechanical dynamics in the same way…

High Energy Physics - Theory · Physics 2015-06-26 M. Reuter

In the realm of fault-tolerant quantum computing, stabilizer operations play a pivotal role, characterized by their remarkable efficiency in classical simulation. This efficiency sets them apart from non-stabilizer operations within the…

Quantum Physics · Physics 2024-07-30 Chengkai Zhu , Zhiping Liu , Chenghong Zhu , Xin Wang

For classical field theories with probabilistic initial conditions the classical field observables are an idealization. Their arbitrarily precise values poorly reflect the characteristic uncertainty in the presence of substantial…

Quantum Physics · Physics 2026-03-06 Christof Wetterich

The application of a classical approach to various quantum problems - the secular perturbation approach to quantization of a hydrogen atom in external fields and a helium atom, the adiabatic switching method for calculation of a…

Quantum Physics · Physics 2015-05-18 Evgeni A. Solov'ev

It is shown that the vacuum state of weakly interacting quantum field theories can be described, in the Heisenberg picture, as a linear combination of randomly distributed incoherent paths that obey classical equations of motion with…

High Energy Physics - Theory · Physics 2009-11-07 Ram Brustein , David H. Oaknin

The main notions of semiclassical scalar electrodynamics in different gauges (Hamiltonian, Couloumb, Lorentz) are discussed. These are semiclassical states, Poincare transformations, fields, observables, gauge equivalence. General…

High Energy Physics - Theory · Physics 2007-05-23 O. Yu. Shvedov

We investigate the classical aspects of Quantum theory and under which description Quantum theory does appear Classical. Although such descriptions or variables are known as "ontological" or "hidden", they are not hidden at all, but are…

Quantum Physics · Physics 2025-01-22 Diego J. Cirilo-Lombardo , Norma G. Sanchez

We study the dynamics of classical and quantum systems undergoing a continuous measurement of position by schematizing the measurement apparatus with an infinite set of harmonic oscillators at finite temperature linearly coupled to the…

Quantum Physics · Physics 2008-11-26 Carlo Presilla , Roberto Onofrio , Marco Patriarca

Classical shadows are a computationally efficient approach to storing quantum states on a classical computer for the purposes of estimating expectation values of local observables, obtained by performing repeated random measurements. In…

Quantum Physics · Physics 2023-05-03 Saumya Shivam , C. W. von Keyserlingk , S. L. Sondhi

We show that the classical mechanics of an algebraic model are implied by its quantizations. An algebraic model is defined, and the corresponding classical and quantum realizations are given in terms of a spectrum generating algebra.…

Quantum Physics · Physics 2007-05-23 Stephen D. Bartlett , David J. Rowe

The ideas behind the nonlocal classical statistical field theory model for the quantized Klein-Gordon field introduced in Morgan(2001, quant-ph/0106141) are extended to accommodate quantum electrodynamics. The anticommutation rules for the…

Quantum Physics · Physics 2007-05-23 P. W. Morgan

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

We discuss the classical statistics of isolated subsystems. Only a small part of the information contained in the classical probability distribution for the subsystem and its environment is available for the description of the isolated…

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