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Related papers: Fast Fermi Acceleration and Entropy Growth

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Magnetic reconnection drives multi-species particle acceleration broadly in space and astrophysics. We perform the first 3D hybrid simulations (fluid electrons, kinetic ions) that contain sufficient scale separation to produce nonthermal…

Solar and Stellar Astrophysics · Physics 2024-01-31 Qile Zhang , Fan Guo , William Daughton , Hui Li , Ari Le , Tai Phan , Mihir Desai

We use microscopic many-body theory to analyze the problem of itinerant ferromagnetism in a repulsive atomic Fermi gas of Hard Spheres. Using simple arguments, we show that the available theoretical predictions for the onset of the…

Quantum Gases · Physics 2015-06-04 F. Arias de Saavedra , F. Mazzanti , J. Boronat , A. Polls

We consider a non-interacting Fermi gas in a combined harmonic and periodic potential. We calculate the energy spectrum and simulate the motion of the gas after sudden replacement of the trap center. For different parameter regimes, the…

Soft Condensed Matter · Physics 2009-11-10 V. Ruuska , P. Torma

This paper investigates the thermodynamic evolution of the universe within the framework of a quadratic equation of state (EoS). Building upon the basis of the quadratic EoS model, as a phenomenological extension to dark energy models, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-28 A. Shahriar , M. Abbasiyan-Motlaq , M. Mohsenzadeh , E. Yusofi

We investigate the energy dynamics of a unitary Fermi gas driven away from equilibrium. The energy is injected into the system by periodically modulating the trapping potential of a spherical unitary Fermi gas, and due to the existence of…

Quantum Gases · Physics 2026-05-15 Xiangchuan Yan , Jing Min , Dali Sun , Shi-Guo Peng , Xin Xie , Xizhi Wu , Kaijun Jiang

We simulate a balanced attractively interacting two-component Fermi gas in a one-dimensional lattice perturbed with a moving potential well or barrier. Using the time-evolving block decimation method, we study different velocities of the…

Quantum Gases · Physics 2015-11-20 A. -M. Visuri , D. -H. Kim , J. J. Kinnunen , F. Massel , P. Törmä

Is it possible that the current cosmic accelerating expansion will turn into a decelerating one? Can this transition be realized by some viable theoretical model that is consistent with the standard Big Bang cosmology? We study a class of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Tianlong Zu , Jiewen Chen , Yang Zhang

We study the quantum evolution of many-body Fermi gases in three dimensions, in arbitrarily large domains. We consider both particles with non-relativistic and with relativistic dispersion. We focus on the high-density regime, in the…

Mathematical Physics · Physics 2023-04-05 Luca Fresta , Marcello Porta , Benjamin Schlein

The subject of this paper is stochastic acceleration by plasma turbulence, a process akin to the original model proposed by Fermi. We review the relative merits of different acceleration models, in particular the so called first order Fermi…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Vahe Petrosian

We propose that non-thermal electrons are efficiently accelerated by first-order Fermi process at the fast shock, as a natural consequence of the new magnetohydrodynamic picture of the flaring region revealed with Yohkoh. An oblique fast…

Astrophysics · Physics 2009-10-30 Saku Tsuneta , Tsuguya Naito

A vast concourse of events and phenomena occur in nature that may be interrelated by a entropy-maximization technique that provides a comprehensible explanation of a range of physical problems, integrating in a new framework the universal…

Classical Physics · Physics 2021-10-18 Mario J Pinheiro

Prethermalization refers to the transient phenomenon where a system thermalizes according to a Hamiltonian that is not the generator of its evolution. We provide here a rigorous framework for quantum spin systems where prethermalization is…

Mathematical Physics · Physics 2017-07-11 Dmitry Abanin , Wojciech De Roeck , Wen Wei Ho , Francois Huveneers

The origin of hard X-ray (HXR) excess emission from clusters of galaxies is still an enigma, whose nature is debated. One of the possible mechanism to produce this emission is the bremsstrahlung model. However, previous analytical and…

High Energy Astrophysical Phenomena · Physics 2015-06-11 D. O. Chernyshov , V. A. Dogiel , C. M. Ko

We study the evolution from few- to many-body physics of fermionic systems in one spatial dimension with attractive pairwise interactions. We determine the detailed form of the momentum distribution, the structure of the one-body density…

Quantum Gases · Physics 2017-10-05 Lukas Rammelmüller , William J. Porter , Jens Braun , Joaquín Drut

In this work we show how friction enables a non-linear energy transfer in a slow-fast Hamiltonian system. We first introduce a paradigmatic system consisting of a weakly coupled fast and slow oscillator that gives rise to a non-linear…

Classical Physics · Physics 2024-12-23 Diego M Fieguth

I review the current status of Fermi acceleration theory at relativistic shocks. I first discuss the relativistic shock jump conditions, then describe the non-relativistic Fermi mechanism and the differences introduced by relativistic…

Astrophysics · Physics 2007-05-23 Yves A. Gallant

The acceleration time scale for the process of first-order Fermi acceleration in relativistic shock waves with oblique magnetic field configurations is investigated by the method of Monte Carlo particle simulations. We demonstrate the…

Astrophysics · Physics 2015-06-24 J. Bednarz , M. Ostrowski

We show that the entanglement entropy associated to a region grows faster than the area of its boundary surface. This is done by proving a special case of a conjecture due to Widom that yields a surprisingly simple expression for the…

High Energy Physics - Theory · Physics 2015-05-18 Robert C. Helling , Wolfgang Spitzer

We propose a new way of quick and very efficient acceleration of protons and/or electrons in relativistic bulk flows. The new mechanism takes advantage of conversion of particles from the charged state (protons or electrons/positrons) into…

Astrophysics · Physics 2009-11-07 E. V. Derishev , F. A. Aharonian , V. V. Kocharovsky , Vl. V. Kocharovsky

The fastest possible collective response of a quantum many-body system is related to its excitations at the highest possible energy. In condensed-matter systems, the corresponding timescale is typically set by the Fermi energy. Taking…

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