1,102 research outputs found
Asymptotics of work distributions in a stochastically driven system
We determine the asymptotic forms of work distributions at arbitrary times
, in a class of driven stochastic systems using a theory developed by Engel
and Nickelsen (EN theory) (arXiv:1102.4505v1 [cond-mat.stat-mech]), which is
based on the contraction principle of large deviation theory. In this paper, we
extend the theory, previously applied in the context of deterministically
driven systems, to a model in which the driving is stochastic. The models we
study are described by overdamped Langevin equations and the work distributions
in the path integral form, are characterised by having quadratic actions. We
first illustrate EN theory, for a deterministically driven system - the
breathing parabola model, and show that within its framework, the Crooks
flucutation theorem manifests itself as a reflection symmetry property of a
certain characteristic polynomial function. We then extend our analysis to a
stochastically driven system, studied in ( arXiv:1212.0704v2
[cond-mat.stat-mech], arXiv:1402.5777v1 [cond-mat.stat-mech]) using a
moment-generating-function method, for both equilibrium and non - equilibrium
steady state initial distributions. In both cases we obtain new analytic
solutions for the asymptotic forms of (dissipated) work distributions at
arbitrary . For dissipated work in the steady state, we compare the large
asymptotic behaviour of our solution to that already obtained in (
arXiv:1402.5777v1 [cond-mat.stat-mech]). In all cases, special emphasis is
placed on the computation of the pre-exponential factor and the results show
excellent agreement with the numerical simulations. Our solutions are exact in
the low noise limit.Comment: 26 pages, 8 figures. Changes from version 1: Several typos and
equations corrected, references added, pictures modified. Version to appear
in EPJ
On certain new exact solutions of a diffusive predator-prey system
We construct exact solutions for a system of two nonlinear partial
differential equations describing the spatio-temporal dynamics of a
predator-prey system where the prey per capita growth rate is subject to the
Allee effect. Using the expansion method, we derive
exact solutions to this model for two different wave speeds. For each wave
velocity we report three different forms of solutions. We also discuss the
biological relevance of the solutions obtained.Comment: Accepted for Publication in Commun. Nonlin. Sci. Num. Sim. (2012
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