Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A New Approach based on Langevin type Equation for Driven Granular Gas
  under Gravity   We propose a novel approach based on a Langevin equation for fluctuating
motion of the center of mass of granular media fluidized by energy injection
from a bottom plate. In this framework, the analytical solution of the Langevin
equation is used to derive analytic expressions for several macroscopic
quantities and the power spectrum for the center of mass. In order to test our
theory, we performed event-driven molecular dynamics simulations for one- and
two-dimensional systems. Energy is injected from a vibrating bottom plate in
the one-dimensional case and from a thermal wall at the bottom in the
two-dimensional case. We found that the theoretical predictions are in good
agreement with the results of those simulations under the assumption that the
fluctuation-dissipation relation holds in the case of nearly elastic collisions
between particles. However, as the inelasticity of the interparticle collisions
increases, the power spectrum for the center of mass obtained by the
simulations gradually deviates from the prediction of theoretical curve.
Connection between this deviation and violation of the fluctuation-dissipation
relation is discussed.

36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th