Zobrazeno 1 - 10
of 635
pro vyhledávání: '"Ruffo, S."'
Publikováno v:
Commun. Nonlinear Sci. Numer. Simul. 60, 115 (2018)
We study the dynamics of Fermi-Pasta-Ulam chains with both harmonic and anharmonic power-law long-range interactions. We show that the dynamics is described in the continuum limit by a generalized fractional Boussinesq differential equation, whose de
Externí odkaz:
http://arxiv.org/abs/1802.00247
Publikováno v:
Phys. Rev. E 96, 062103 (2017)
We study inequivalence of canonical and microcanonical ensembles in the mean-field Blume-Emery-Griffiths model. This generalizes previous results obtained for the Blume-Capel model. The phase diagram strongly depends on the value of the biquadratic e
Externí odkaz:
http://arxiv.org/abs/1708.01082
Publikováno v:
European Physical Journal - Special Topics, EDP Sciences: EPJ, 2007, 147, pp.3
We present a detailed analysis of the modulational instability of the zone-boundary mode for one and higher-dimensional Fermi--Pasta--Ulam (FPU) lattices. The growth of the instability is followed by a process of relaxation to equipartition, which we
Externí odkaz:
http://arxiv.org/abs/1504.01490
Understanding the relaxation of a system towards equilibrium is a longstanding problem in statistical mechanics. Here we address the role of long-range interactions in this process by considering a class of two-dimensional or geophysical flows where
Externí odkaz:
http://arxiv.org/abs/1503.07904
Publikováno v:
Europhysics Letters 104, 17011 (2013)
We have studied needle shaped three-dimensional classical spin systems with purely dipolar interactions in the microcanonical ensemble, using both numerical simulations and analytical approximations. We have observed spontaneous magnetization for dif
Externí odkaz:
http://arxiv.org/abs/1305.5331
Publikováno v:
Phys. Rev. Lett. 111, 117202 (2013)
In a coupled ferroelectric/ferromagnetic system, i.e. a composite multiferroic, the propagation of magnetic or ferroelectric excitations across the whole structure is a key issue for applications. Of a special interest is the dynamics of localized ma
Externí odkaz:
http://arxiv.org/abs/1301.3802
Publikováno v:
J. Stat. Mech. (2011) P03022
The Vlasov equation is well known to provide a good description of the dynamics of mean-field systems in the $N \to \infty$ limit. This equation has an infinity of stationary states and the case of {\it homogeneous} states, for which the single-parti
Externí odkaz:
http://arxiv.org/abs/1010.4647
Publikováno v:
Physics Reports 480 (2009), pp. 57-159
The two-body potential of systems with long-range interactions decays at large distances as $V(r)\sim 1/r^\alpha$, with $\alpha\leq d$, where $d$ is the space dimension. Examples are: gravitational systems, two-dimensional hydrodynamics, two-dimensio
Externí odkaz:
http://arxiv.org/abs/0907.0323
Publikováno v:
Physica A 385, 233-248, 2007
We calculate the thermodynamic entropy of the mean-field $\phi^4$ spin model in the microcanonical ensemble as a function of the energy and magnetization of the model. The entropy and its derivative are obtained from the theory of large deviations, a
Externí odkaz:
http://arxiv.org/abs/cond-mat/0702004
The thermodynamic and dynamical properties of an Ising model with both short range and long range, mean field like, interactions are studied within the microcanonical ensemble. It is found that the relaxation time of thermodynamically unstable states
Externí odkaz:
http://arxiv.org/abs/cond-mat/0508604