46 citations · 314 across the 45 of their papers we have counts for
20 papers · 1 filter
Cooling rate and glassy behavior in the Fermi--Pasta--Ulam system
Matteo Razza, Andrea Carati, Luigi Galgani
In this work, we numerically studied the cooling process of a Fermi--Pasta--Ulam system, which occurs when the FPU system is placed in contact with a gas whose temperature is r…
Spectra as a classical phenomenon, and the Einstein classical program
Andrea Carati, Luigi Galgani, Fabrizio Gangemi
According to Born (\emph{Atomic Physics, page 103}), spectra are \emph{``quantum phenomena, which from a classical standpoint are perfectly unintelligible''}. However we illustrate…
A dynamical approach to the - displacive transition of quartz
Andrea Carati, Fabrizio Gangemi, Roberto Gangemi +1
General features of the transition of quartz are investigated. Molecular dynamics methods are mainly used, an analytic treatment being deferred to a work in preparation. A ba…
Tsallis distributions, their relaxations and the relation , in the dynamical fluctuations of a classical model of a crystal
Andrea Carati, Luigi Galgani, Fabrizio Gangemi +1
We report the results of a numerical investigation, performed in the frame of dynamical systems' theory, for a realistic model of a ionic crystal for which, due to the presence of…
Approach to equilibrium via Tsallis distributions in a realistic ionic--crystal model and in the FPU model
Andrea Carati, Luigi Galgani, Fabrizio Gangemi +1
In Statistical Mechanics, Tsallis distributions were apparently conceived in connection with systems presenting long--range interactions. In fact, they were observed in numerical c…
Relaxation times and ergodicity properties in a realistic ionic--crystal model, and the modern form of the FPU problem
Andrea Carati, Luigi Galgani, Fabrizio Gangemi +1
It is well known that Gibbs' statistical mechanics is not justified for systems presenting long-range interactions, such as plasmas or galaxies. In a previous work we considered a…
Classical infrared spectra of ionic crystals and their relevance for statistical mechanics
Andrea Carati, Luigi Galgani, Alberto Maiocchi +2
It was recently shown that the experimental infrared spectra of ionic crystals at room temperature are very well reproduced by classical realistic models, and here new results are…
Chopping time of the FPU -model
Andrea Carati, Antonio Ponno
We study, both numerically and analytically, the time needed to observe the breaking of an FPU -chain in two or more pieces, starting from an unbroken configuration at a given t…
The Fermi-Pasta-Ulam system as a model for glasses
Andrea Carati, Alberto Maiocchi, Luigi Galgani +1
We show that the standard Fermi--Pasta--Ulam system, with a suitable choice for the interparticle potential, constitutes a model for glasses, and indeed an extremely simple and man…
Classical microscopic theory of dispersion, emission and absorption of light in dielectrics
Andrea Carati, Luigi Galgani
This paper is a continuation of a recent one in which, apparently for the first time, the existence of polaritons in ionic crystals was proven in a microscopic electrodynamic theor…
Classical microscopic theory of polaritons in ionic crystals
A. Lerose, A. Sanzeni, A Carati +1
It is well known that the optical branches of the dispersion curves of ionic crystals exhibit a polaritonic feature, i.e., a splitting about the electromagnetic dispersion line $ω=…
Statistical Thermodynamics for metaequilibrium or metastable states
A. Carati, A. Maiocchi, L. Galgani
We show how statistical thermodynamics can be formulated in situations in which thermodynamics applies, while equilibrium statistical mechanics does not. A typical case is, in the…
Transition to chaos in magnetized, weakly coupled plasmas
Andrea Carati, Francesco Benfenati, Alberto Maiocchi +2
We report the results of numerical simulations for a model of a one component plasma (a system of N point electrons with mutual Coulomb interactions) in a uniform stationary magnet…
Density limit in a first principles model of a magnetized plasma in the Debye--Hückel approximation
A. Carati, M. Zuin, A. Maiocchi +3
A crucial problem concerning a large variety of fusion devices is that the confinement due to an external magnetic field is lost above a critical density, while a widely accepted f…
Relaxation properties in classical diamagnetism
A. Carati, F. Benfenati, L. Galgani
In the present paper the problem of the relaxation of magnetization to equilibrium (i.e., with no magnetization) is investigated numerically for a variant of the well-known model i…
FPU phenomenon for generic initial data
A. Carati, L. Galgani, A. Giorgilli +1
The well known FPU phenomenon (lack of attainment of equipartition of the mode--energies at low energies, for some exceptional initial data) suggests that the FPU model does not ha…
Metastable states in the FPU system
A. Carati, L. Galgani
In this letter we report numerical results giving, as a function of time, the energy fluctuation of a Fermi-Pasta-Ulam system in dynamical contact with a heat bath, the initial dat…
On the definition of temperature using time--averages
A. Carati
This paper is a natural continuation of a previous one by the author, which was concerned with the foundations of statistical thermodynamics far from equilibrium. One of the proble…
Thermodynamics and time-average
A. Carati
For a dynamical system far from equilibrium, one has to deal with empirical probabilities defined through time-averages, and the main problem is then how to formulate an appropriat…
On the definition of temperature in FPU systems
A. Carati, P. Cipriani, L. Galgani
It is usually assumed, in classical statistical mechanics, that the temperature should coincide, apart from a suitable constant factor, with the mean kinetic energy of the particle…