Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Relaxation of a test particle in systems with long-range interactions:
  diffusion coefficient and dynamical friction   We study the relaxation of a test particle immersed in a bath of field
particles interacting via weak long-range forces. To order 1/N in the $N\to
+\infty$ limit, the velocity distribution of the test particle satisfies a
Fokker-Planck equation whose form is related to the Landau and Lenard-Balescu
equations in plasma physics. We provide explict expressions for the diffusion
coefficient and friction force in the case where the velocity distribution of
the field particles is isotropic. We consider (i) various dimensions of space
$d=3,2$ and 1 (ii) a discret spectrum of masses among the particles (iii)
different distributions of the bath including the Maxwell distribution of
statistical equilibrium (thermal bath) and the step function (water bag).
Specific applications are given for self-gravitating systems in three
dimensions, Coulombian systems in two dimensions and for the HMF model in one
dimension.

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The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
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The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
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The categories of this paper are: q-bio
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The categories of this paper are: q-fin
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The categories of this paper are: funct-an
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The categories of this paper are: dg-ga
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-lat