Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the thermodynamic origin of the Hawking entropy and a measurement of
  the Hawking temperature   In the spherically symmetric case the Einstein field equations take on their
simplest form for a matter-density rho = 1 / (8 pi r^2), from which a radial
metric coefficient g_{rr} \propto r follows. The boundary of an object with
such an interior matter-density is situated slightly outside of its
gravitational radius. Its surface-redshift scales with z \propto \sqrt{r}, so
that any such large object is practically indistinguishable from a black hole,
as seen from exterior space-time. The interior matter has a well defined
temperature, T \propto 1 / \sqrt{r}. Under the assumption, that the interior
matter can be described as an ultra-relativistic gas, the object's total
entropy and its temperature at infinity can be calculated by microscopic
statistical thermodynamics. They are equal to the Hawking result up to a
possibly different constant factor. The simplest solution of the field
equations with rho = 1 / (8 pi r^2) is the so called holographic solution,
short "holostar". It has an interior string equation of state. The strings are
densely packed, explaining why the solution does not collapse to a singularity.
The holographic solution has been shown to be a very accurate model for the
universe as we see it today in Ref[7]. The factor relating the holostar's
temperature at infinity to the Hawking temperature can be expressed in terms
the holostar's interior (local) radiation temperature and its (local)
matter-density, allowing an experimental verification of the Hawking
temperature law. Using the recent experimental data for the CMBR-temperature
and the total matter-density in the universe measured by WMAP, the Hawking
formula is verified to an accuracy of 1%.

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The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: comp-gas
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The categories of this paper are: eess
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The categories of this paper are: math-ph
9
The categories of this paper are: nlin
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The categories of this paper are: q-bio
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The categories of this paper are: plasm-ph
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
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The categories of this paper are: physics
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The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph