Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hybrid brane worlds in the Salam-Sezgin model   We construct a 6-dimensional warped brane world compactification of the
Salam-Sezgin supergravity model by generalizing an earlier hybrid Kaluza-Klein
/ Randall-Sundrum construction [hep-th/0109099]. In this construction the
observed universe is interpreted as a 4-brane in six dimensions, with a
Kaluza-Klein spatial direction in addition to the usual three noncompact
spatial dimensions. This construction is distinct from other brane world
constructions in six dimensions, which introduce the universe as a 3-brane
corresponding to a topological defect in six dimensions, or which require a
particular configuration of matter fields on the brane. We demonstrate that the
model reproduces localized gravity on the brane in the expected form of a
Newtonian potential with Yukawa-type corrections. We show that allowed
parameter ranges include values which potentially solve the hierarchy problem.
An exact nonlinear gravitational wave solution on the background is exhibited.
The class of solutions given applies to Ricci-flat geometries in four
dimensions, and consequently includes brane world realizations of the
Schwarzschild and Kerr black holes as particular examples. Arguments are given
which suggest that the hybrid compactification of the Salam-Sezgin model can be
extended to reductions to arbitrary Einstein space geometries in four
dimensions.

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The categories of this paper are: q-alg
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The categories of this paper are: mtrl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: econ
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The categories of this paper are: plasm-ph
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The categories of this paper are: stat
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The categories of this paper are: solv-int
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The categories of this paper are: q-bio
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The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
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The categories of this paper are: cs
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The categories of this paper are: nlin
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The categories of this paper are: physics
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The categories of this paper are: quant-ph
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The categories of this paper are: adap-org