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Related papers: Comparison of Boltzmann Equations with Quantum Dyn…

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We present kinetic equations that describe the evolution of O(N)-symmetric real scalar quantum fields out of thermal equilibrium in a systematic nonperturbative approximation scheme. This description starts from the 1/N-expansion of the 2PI…

High Energy Physics - Phenomenology · Physics 2007-05-23 Markus Michael Muller

We introduce evolved quantum Boltzmann machines as a variational ansatz for quantum optimization and learning tasks. Given two parameterized Hamiltonians $G(\theta)$ and $H(\phi)$, an evolved quantum Boltzmann machine consists of preparing…

Quantum Physics · Physics 2026-03-18 Michele Minervini , Dhrumil Patel , Mark M. Wilde

We present a numerical analysis of the cosmological evolution of scalar field dark matter (SFDM) in the Boltzmann code $\texttt{CLASS}$, based on a dynamical system analysis of previous works. We show a detailed study of the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-13 L. Arturo Ureña-López , Francisco X. Linares Cedeño

In this more pedagogical study we want to elucidate on stochastic aspects inherent to the (non-)equilibrium real time Green's function description (or `closed time path Green's function' -- CTPGF) of transport equations, the so called…

High Energy Physics - Phenomenology · Physics 2014-11-17 Carsten Greiner , Stefan Leupold

We consider the time evolution of nonequilibrium quantum scalar fields in the O(N) model, using the next-to-leading order 1/N expansion of the 2PI effective action. A comparison with exact numerical simulations in 1+1 dimensions in the…

High Energy Physics - Phenomenology · Physics 2010-02-04 Gert Aarts , Jurgen Berges

The quantum corrections related to the ideal gas model that are often considered are those which are related to the particles nature: bosons or fermions. These corrections lead respectively to the Bose-Einstein and Fermi-Dirac statistics.…

In a recent article, Werndl and Frigg discuss the relationship between the Boltzmannian and Gibbsian framework of statistical mechanics, addressing in particular the question when equilibrium values calculated in both frameworks agree. In…

History and Philosophy of Physics · Physics 2018-11-09 Dustin Lazarovici

Quantum computing raises the possibility of solving a variety of problems in physics that are presently intractable. A number of such problems involves the physics of systems in or near thermal equilibrium. There are two main ways to…

Quantum Physics · Physics 2023-08-16 Carter Ball , Thomas D. Cohen

In this paper, we consider the capabilities of the Boltzmann equation with the Shakhov and ellipsoidal models for the collision term to capture the characteristics of rarefied gas flows. The benchmark is performed by comparing the results…

Computational Physics · Physics 2020-07-21 Victor E. Ambrus , Felix Sharipov , Victor Sofonea

A theory of quantum jumps is developed by using a new asymmetric equation, which is complementary to the Schr\"odinger equation. The new equation displays Bohr's rules for quantum jumps, and its solutions demonstrate that once a quantum…

General Physics · Physics 2025-09-23 Z. E. Musielak

The fluid equations for the baryon-electron system in an expanding universe are derived from the Boltzmann equation. The effect of the Compton interaction is taken into account properly in order to evaluate the photon-electron collisional…

Astrophysics · Physics 2009-10-30 Kazuhiro Yamamoto , Naoshi Sugiyama , Humitaka Sato

Recently developed series representations of the Boltzmann operator are used to obtain Quantum Mechanical results for the matrix elements, <x| exp(-{\beta} H)|x>, of the imaginary time propagator. The calculations are done for two different…

Chemical Physics · Physics 2012-03-28 Mahir E. Ocak

Spectral methods, thanks to their high accuracy and the possibility to use fast algorithms, represent an effective way to approximate the collisional kinetic equations of Boltzmann type, such as the Boltzmann-Nordheim equation. This…

Numerical Analysis · Mathematics 2021-10-27 Alexandre Mouton , Thomas Rey

Within the framework of Tsallis statistics with q ~ 1, we construct a perturbation theory for treating relativistic quantum field systems. We find that there appear initial correlations, which do not exist in the Boltzmann-Gibbs statistics.…

High Energy Physics - Theory · Physics 2008-11-26 H. Kohyama , A. Niegawa

Boltzmann machine is a powerful tool for modeling probability distributions that govern the training data. A thermal equilibrium state is typically used for Boltzmann machine learning to obtain a suitable probability distribution. The…

Most versions of classical physics imply that if the 4-volume of the entire space-time is infinite or at least extremely large, then random fluctuations in the matter will by coincidence create copies of us in remote places, so called…

General Relativity and Quantum Cosmology · Physics 2018-12-06 Roderich Tumulka

A general lattice Boltzmann (LB) model is proposed for solving nonlinear partial differential equations with the form $\partial_t \phi+\sum_{k=1}^{m} \alpha_k \partial_x^k \Pi_k (\phi)=0$, where $\alpha_k$ are constant coefficients, and…

Computational Physics · Physics 2018-01-17 Baochang Shi , Hanzhong He , Zhaoli Guo

Gradient expansions in quantum transport equations of a Kadanoff-Baym form have been reexamined. We have realized that in a consistent approach the expansion should be performed also inside of the self-energy in the scattering integrals of…

Statistical Mechanics · Physics 2009-10-28 Petr Král

We argue that one can model deviations from the ensemble average in non-equilibrium statistical mechanics by promoting the Boltzmann equation to an equation in terms of {\em functionals} , representing possible candidates for phase space…

Statistical Mechanics · Physics 2024-03-13 Giorgio Torrieri

It is showed that, in general, classical and quantum dispersion relations are different due to the presence of the Bohm potential. There are exact particular solutions of the quantum (wave) theory which obey the classical dispersion…

Quantum Physics · Physics 2021-02-05 Sergio A. Hojman , Felipe A. Asenjo
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