Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Nonlinear Master Equation for Open Quantum Systems   A nonlinear master equation is derived, reflecting properly the entropy of
open quantum systems. In contrast to linear alternatives, its equilibrium
solution is exactly the canonical Gibbs density matrix. The corresponding
nonlinear equation for the Wigner function accounts rigorously for the
thermo-quantum entropy. It reduces at large friction to the Smoluchowski-Bohm
equation in the coordinate subspace, which reflects the stochastic
Langevin-Bohm dynamics. The previously derived Maxwell-Heisenberg relation for
the nonequilibrium momentum dispersion of quantum Brownian particles is
confirmed as well as the related quantum generalization of the classical
Einstein law of Brownian motion.

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The categories of this paper are: physics
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ