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Related papers: Microcanonical vs. canonical thermodynamics

200 papers

According to thermodynamics, the specific heat of Boltzmannian short-range interacting systems is a positive quantity. Less intuitive properties are instead displayed by systems characterized by long-range interactions. In that case, the…

Statistical Mechanics · Physics 2015-05-18 F. Staniscia , A. Turchi , D. Fanelli , P. H. Chavanis , G. De Ninno

We establish an analytical criterion for dynamical thermalization within harmonic systems, applicable to both classical and quantum models. Specifically, we prove that thermalization of various observables, such as particle energies in…

Statistical Mechanics · Physics 2025-07-29 Marco Cattaneo , Marco Baldovin , Dario Lucente , Paolo Muratore-Ginanneschi , Angelo Vulpiani

The physical meaning of entropy is analyzed in the context of statistical, nuclear, atomic physics and cosmology. Only the microcanonical Boltzmann entropy leads to no contradictions in several simple, elementary and for thermodynamics…

Nuclear Theory · Physics 2007-05-23 D. H. E. Gross

Molecular or condensed matter systems are often well approximated by hybrid quantum-classical models: the electrons retain their quantum character, whereas the ions are considered to be classical particles. We discuss various alternative…

Chemical Physics · Physics 2021-05-07 J. L. Alonso , C. Bouthelier , A. Castro , J. Clemente-Gallardo , J. A. Jover-Galtier

In this work we consider black hole solutions to Einstein theory coupled to a nonlinear power-law electromagnetic field with a fixed exponent value. We study the extended phase space thermodynamics in canonical and grand canonical ensembles…

General Relativity and Quantum Cosmology · Physics 2021-12-08 Ramon Becar , P. A. Gonzalez , Joel Saavedra , Yerko Vasquez , Bin Wang

The standard assumption for the equilibrium microcanonical state in quantum mechanics, that the system must be in one of the energy eigenstates, is weakened so as to allow superpositions of states. The weakened form of the microcanonical…

Quantum Physics · Physics 2007-05-23 Dorje C Brody , Daniel W Hook , Lane P Hughston

The classical wave-particle Hamiltonian is considered in its generalized version, where two modes are assumed to interact with the co-evolving charged particles. The equilibrium statistical mechanics solution of the model is worked out…

Statistical Mechanics · Physics 2015-06-18 Tarcísio N. Teles , Duccio Fanelli , Stefano Ruffo

Fluctuations of charged particle number are studied in the canonical ensemble. In the infinite volume limit the fluctuations in the canonical ensemble are different from the fluctuations in the grand canonical one. Thus, the well-known…

Nuclear Theory · Physics 2009-11-10 V. V. Begun , M. Gazdzicki , M. I. Gorenstein , O. S. Zozulya

Two approaches to describe the thermodynamics of a subsystem that interacts with a thermal bath are considered. Within the first approach, the mean system energy $E_{S}$ is identified with the expectation value of the system Hamiltonian,…

Statistical Mechanics · Physics 2009-07-08 M. F. Gelin , M. Thoss

This is a note intended to complement our paper (nucl-th/0504010) and addressed to the attention of QGP workers interested in bag models, Hagedorn spectra, and the like. It tries to show that with a Hagedorn-like experimental spectrum the…

Nuclear Theory · Physics 2007-05-23 L. G. Moretto , K. A. Bugaev , J. B. Elliott , L. Phair

Heat can flow from cold to hot at any phase separation. Therefore Lynden-Bell's gravo-thermal catastrophe must be reconsidered. The original objects of Thermodynamics, the separation of phases at first order phase transitions, like boiling…

Statistical Mechanics · Physics 2007-05-23 D. H. E. Gross

We study a quantum spin system on the $d$-dimensional hypercubic lattice $\Lambda$ with $N=L^d$ sites with periodic boundary conditions. We take an arbitrary translation invariant short-ranged Hamiltonian. For this system, we consider both…

Statistical Mechanics · Physics 2018-08-02 Hal Tasaki

We investigate how the temperature calculated from the microcanonical entropy compares with the canonical temperature for finite isolated quantum systems. We concentrate on systems with sizes that make them accessible to numerical exact…

Statistical Mechanics · Physics 2023-04-05 Phillip C. Burke , Masudul Haque

It has been proved for a class of mean-field and long-range systems that the concavity of the thermodynamic entropy determines whether the microcanonical and canonical ensembles are equivalent at the level of their equilibrium states, i.e.,…

Statistical Mechanics · Physics 2011-11-29 Hugo Touchette

Microcanonical description is characterized by the presence of an internal symmetry closely related with the dynamical origin of this ensemble: the reparametrization invariance. Such symmetry possibilities the development of a non…

Statistical Mechanics · Physics 2007-05-23 L. Velazquez , F. Guzman

When addressing the thermodynamics of finite-sized systems, one must specify whether one wants to fix conserved charges to a sharp value or whether one is content to fix their thermodynamic average. In other words, contrary to the…

High Energy Physics - Phenomenology · Physics 2016-09-01 Michael Engelhardt

We consider a system weakly interacting with a bath as a thermodynamic setting to establish a quantum foundation of statistical physics. It is shown that even if the composite system is initially in an arbitrary nonequilibrium pure quantum…

Quantum Physics · Physics 2010-04-28 Jaeyoon Cho , M. S. Kim

For the spherical model with nearest-neighbour interactions, the microcanonical entropy s(e,m) is computed analytically in the thermodynamic limit for all accessible values of the energy e and the magnetization m per spin. The entropy…

Statistical Mechanics · Physics 2009-12-11 Michael Kastner

We propose the use of microcanonical analyses for numerical studies of peptide aggregation transitions. Performing multicanonical Monte Carlo simulations of a simple hydrophobic-polar continuum model for interacting heteropolymers of finite…

Soft Condensed Matter · Physics 2009-11-13 Christoph Junghans , Michael Bachmann , Wolfhard Janke

The phase space of quantum mechanics can be viewed as the complex projective space endowed with a Kaehlerian structure given by the Fubini-Study metric and an associated symplectic form. We can then interpret the Schrodinger equation as…

Quantum Physics · Physics 2009-10-30 D. C. Brody , L. P. Hughston