Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Universal Bound on Dynamical Relaxation Times and Black-Hole Quasinormal
  Ringing   From information theory and thermodynamic considerations a universal bound on
the relaxation time $\tau$ of a perturbed system is inferred, $\tau \geq
\hbar/\pi T$, where $T$ is the system's temperature. We prove that black holes
comply with the bound; in fact they actually {\it saturate} it. Thus, when
judged by their relaxation properties, black holes are the most extreme objects
in nature, having the maximum relaxation rate which is allowed by quantum
theory.

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The categories of this paper are: plasm-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
3
The categories of this paper are: physics
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: q-fin
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The categories of this paper are: nlin
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The categories of this paper are: cmp-lg
2
The categories of this paper are: math