Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Statistical Mechanical Interpretation of Black Hole Entropy Based on
  an Orthonormal Frame Action   Carlip has shown that the entropy of the three-dimensional black hole has its
origin in the statistical mechanics of microscopic states living at the
horizon. Beginning with a certain orthonormal frame action, and applying
similar methods, I show that an analogous result extends to the (Euclidean)
black hole in any spacetime dimension. However, this approach still faces many
interesting challenges, both technical and conceptual.

23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
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The categories of this paper are: dg-ga
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The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph