Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Homogeneous cooling of rough, dissipative particles: Theory and
  simulations   We investigate freely cooling systems of rough spheres in two and three
dimensions. Simulations using an event driven algorithm are compared with
results of an approximate kinetic theory, based on the assumption of a
generalized homogeneous cooling state. For short times $t$, translational and
rotational energy are found to change linearly with $t$. For large times both
energies decay like $t^{-2}$ with a ratio independent of time, but not
corresponding to equipartition. Good agreement is found between theory and
simulations, as long as no clustering instability is observed. System
parameters, i.e. density, particle size, and particle mass can be absorbed in a
rescaled time, so that the decay of translational and rotational energy is
solely determined by normal restitution and surface roughness.

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The categories of this paper are: q-bio
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The categories of this paper are: q-alg
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The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ex
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The categories of this paper are: cs
37
The categories of this paper are: supr-con
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The categories of this paper are: econ
26
The categories of this paper are: bayes-an
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The categories of this paper are: nucl-th
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The categories of this paper are: solv-int
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The categories of this paper are: chao-dyn
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The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin