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In quantum electrodynamics a classical part of the S-matrix is normally factored out in order to obtain a quantum remainder that can be treated perturbatively without the occurrence of infrared divergences. However, this separation, as…

Quantum Physics · Physics 2014-11-18 Henry P. Stapp

Gaussian quantum systems exhibit many explicitly quantum effects but can be simulated classically. Using both the Hilbert space (Koopman) and the phase-space (Moyal) formalisms we investigate how robust this classicality is. We find…

Quantum Physics · Physics 2017-02-23 Aida Ahmadzadegan , Robert B. Mann , Daniel R. Terno

Some of the most enduring questions in physics--including the quantum measurement problem and the quantization of gravity--involve the interaction of a quantum system with a classical environment. Two linearly coupled harmonic oscillators…

Quantum Physics · Physics 2007-05-23 Rachael M. McDermott , Ian H. Redmount

We study the variance in the measurement of observables during scattering events, as computed using amplitudes. The classical regime, characterised by negligible uncertainty, emerges as a consequence of an infinite set of relationships…

High Energy Physics - Theory · Physics 2024-05-30 Andrea Cristofoli , Riccardo Gonzo , Nathan Moynihan , Donal O'Connell , Alasdair Ross , Matteo Sergola , Chris D. White

In this article, we only consider finite effect algebras. We define the concepts of classical and quantum effect algebras and show that an effect algebra $E$ is classical if and only if there exists an observable that measures every effect…

Quantum Physics · Physics 2024-07-16 Stan Gudder

Classical theory asserts that several electromagnetic waves cannot interact with matter if they interfere destructively to zero, whereas quantum mechanics predicts a nontrivial light-matter dynamics even when the average electric field…

Classical physics is about real objects, like apples falling from trees, whose motion is governed by Newtonian laws. In standard Quantum Mechanics only the wave function or the results of measurements exist, and to answer the question of…

Quantum Physics · Physics 2016-08-16 Valia Allori , Detlef Dürr , Shelly Goldstein , Nino Zanghí

We derive an equation for the current of particles in energy space; particles are subject to a mean field effective potential that may represent quantum effects. From the assumption that non-interacting particles imply a free diffusion…

Statistical Mechanics · Physics 2017-01-04 Miguel Hoyuelos , Pablo Sisterna

Quantum particles can be obtained from a classical probability distribution in phase space by a suitable coarse graining, whereby simultaneous classical information about position and momentum can be lost. For a suitable time evolution of…

Quantum Physics · Physics 2015-05-18 C. Wetterich

In this article we propose a solution to the measurement problem in quantum mechanics. We point out that the measurement problem can be traced to an a priori notion of classicality in the formulation of quantum mechanics. If this notion of…

Quantum Physics · Physics 2008-11-26 Olaf Dreyer

The relation that exists in quantum mechanics among action variables, angle variables and the phases of quantum states is clarified, by referring to the system of a generalized oscillator. As a by-product, quantum-mechanical meaning of the…

High Energy Physics - Theory · Physics 2007-05-23 M. Omote , S. Sakoda , S. Kamefuchi

We consider the motion of a classical particle under the influence of a random potential on R^d, in particular the distribution of asymptotic velocities and the question of ergodicity of time evolution.

Mathematical Physics · Physics 2019-02-20 Andreas Knauf , Christoph Schumacher

t is well known that the difference between Quantum Mechanics and Classical Theory appears most crucially in the non Classical spin half of the former theory and the Wilson-Sommerfelt quantization rule. We argue that this is symptomatic of…

General Physics · Physics 2007-05-23 B. G. Sidharth

Some consequences of a fully classical unified theory of gravity and electromagnetism are worked out for the electromagnetic sector such as the occurrence of classical light beams with spin and orbital angular momenta that are topologically…

Optics · Physics 2016-05-27 Partha Ghose , Anirban Mukherjee

A formal symmetry between generalized coordinates and momenta is postulated to formulate classical and quantum theories of a particle coupled to an Abelian gauge field. It is shown that the symmetry (a) requires the field to have dynamic…

Quantum Physics · Physics 2009-05-17 Partha Ghose

The paper pursues two aims. First, to revisit the classical electromagnetic mass theory and develop it further by making use of a corollary of general relativity - that the propagation of light in non-inertial reference frames is…

Classical Physics · Physics 2011-11-18 Vesselin Petkov

On the basis of extensive numerical studies it is argued that there are strong analogies between the probabilistic behavior of quantum systems defined by Hermitian Hamiltonians and the deterministic behavior of classical mechanical systems…

High Energy Physics - Theory · Physics 2010-05-28 Carl M. Bender , Dorje C. Brody , Daniel W. Hook

A proposal of an algebraic model for the relation between a quantum environment and certain classical particle system is given. The quantum environment is described by a category of possible quantum states, the initial particle system is…

Quantum Algebra · Mathematics 2007-05-23 Wladyslaw Marcinek

Heisenberg's uncertainty principle is often cited as an example of a "purely quantum" relation with no analogue in the classical limit where $\hbar \to 0$. However, this formulation of the classical limit is problematic for many reasons,…

Quantum Physics · Physics 2021-02-23 Viola Gattus , Sotirios Karamitsos

The singularity theorems of classical general relativity are briefly reviewed. The extent to which their conclusions might still apply when quantum theory is taken into account is discussed. There are two distinct quantum loopholes: quantum…

General Relativity and Quantum Cosmology · Physics 2007-05-23 L. H. Ford