scholarly journals One-dimensional arrays of oscillators: Energy localization in thermal equilibrium

1999 ◽  
Vol 111 (4) ◽  
pp. 1373-1384 ◽  
Author(s):  
Ramon Reigada ◽  
Aldo H. Romero ◽  
Antonio Sarmiento ◽  
Katja Lindenberg
Keyword(s):  
Thermal Equilibrium ◽  
Energy Localization ◽  
One Dimensional

scholarly journals Undecidability in quantum thermalization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Naoto Shiraishi ◽  
Keiji Matsumoto
Keyword(s):  
Turing Machine ◽  
Thermal Equilibrium ◽  
General Theorem ◽  
Nearest Neighbour ◽  
Many Body ◽  
Initial State ◽  
One Dimensional ◽  
Universal Turing Machine ◽  
Many Body Systems ◽  
Neighbour Interaction

AbstractThe investigation of thermalization in isolated quantum many-body systems has a long history, dating back to the time of developing statistical mechanics. Most quantum many-body systems in nature are considered to thermalize, while some never achieve thermal equilibrium. The central problem is to clarify whether a given system thermalizes, which has been addressed previously, but not resolved. Here, we show that this problem is undecidable. The resulting undecidability even applies when the system is restricted to one-dimensional shift-invariant systems with nearest-neighbour interaction, and the initial state is a fixed product state. We construct a family of Hamiltonians encoding dynamics of a reversible universal Turing machine, where the fate of a relaxation process changes considerably depending on whether the Turing machine halts. Our result indicates that there is no general theorem, algorithm, or systematic procedure determining the presence or absence of thermalization in any given Hamiltonian.

The action of Vlasov waves on the velocity distribution in a plasma

1961 ◽  
Vol 10 (3) ◽  
pp. 473-479 ◽  
Author(s):  
J. W. Dungey
Keyword(s):  
Magnetic Field ◽  
Phase Space ◽  
Velocity Distribution ◽  
Thermal Equilibrium ◽  
Limited Range ◽  
Dimensional Model ◽  
One Dimensional ◽  
A Current

A one-dimensional model with no magnetic field is considered. It is supposed that the plasma starts in thermal equilibrium and then a current is forced to grow. Instability leads to the growth of waves, which are shown to stir the distribution in phase space, but only over a limited range of velocity. It is concluded that in order to restore stability the energy in the wave must become comparable to the energy of drift.

scholarly journals Intrinsic energy localization through discrete gap breathers in one-dimensional diatomic granular crystals

2010 ◽  
Vol 82 (5) ◽  
Author(s):  
G. Theocharis ◽  
N. Boechler ◽  
P. G. Kevrekidis ◽  
S. Job ◽  
Mason A. Porter ◽  
...  
Keyword(s):  
Energy Localization ◽  
One Dimensional ◽  
Granular Crystals ◽  
Intrinsic Energy

scholarly journals Undecidability in quantum thermalization

2021 ◽  
Author(s):  
Naoto Shiraishi ◽  
Keiji Matsumoto
Keyword(s):  
Turing Machine ◽  
Thermal Equilibrium ◽  
General Theorem ◽  
Nearest Neighbour ◽  
Many Body ◽  
Initial State ◽  
One Dimensional ◽  
Universal Turing Machine ◽  
Many Body Systems ◽  
Neighbour Interaction

Abstract The investigation of thermalization in isolated quantum many-body systems has a long history, dating back to the time of developing statistical mechanics. Most quantum many-body systems in nature are considered to thermalize, while some never achieve thermal equilibrium. The central problem is to clarify whether a given system thermalizes, which has been addressed previously, but not resolved. Here, we show that this problem is undecidable. The resulting undecidability even applies when the system is restricted to one-dimensional shift-invariant systems with nearest-neighbour interaction, and the initial state is a fixed product state. We construct a family of Hamiltonians encoding dynamics of a reversible universal Turing machine, where the fate of a relaxation process changes considerably depending on whether the Turing machine halts. Our result indicates that there is no general theorem, algorithm, or systematic procedure determining the presence or absence of thermalization in any given Hamiltonian.

scholarly journals A phase-changing dry snowpack model

1995 ◽  
Vol 41 (137) ◽  
pp. 11-29 ◽  
Author(s):  
J.M.N.T. Gray ◽  
L.W. Morland ◽  
E.M. Morris
Keyword(s):  
Phase Change ◽  
Time Scale ◽  
Thermal Equilibrium ◽  
Iterative Procedure ◽  
Pore Space ◽  
Momentum Balance ◽  
System Of Equations ◽  
Leading Order ◽  
One Dimensional ◽  
Bulk Energy

AbstractAn interacting continua framework is adopted to model a dry snow park, which is viewed as a three-constituent mixture composed of an ice matrix whose pore space is occupied by water vapour and dry air. We focus on the response of a one-dimensional vertical snowpack to changes in pressure and temperature at its surface. The time-scale of the surface forcing is assumed to be much longer than the time-scale for thermal transfers and phase change to take place. The constituents are, therefore, in thermal equilibrium with a common temperature Τ which is governed by a single bulk-energy balance. In addition, each constituent satisfies a mass and momentum balance. The constitutive postulates and external prescriptions necessary to close the system of equations are discussed in detail. Non-dimensional variables are then introduced formally to draw out the major balances in the equations and construct a reduced system that accurately models the dominant features in the snowpack. It is shown how the effects of phase change enter the leading-order balance. An iterative procedure is constructed to solve the system. Illustrations for the case of a sinusoidal annual temperature gradient imposed at the surface are presented.

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