Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: AdS and stabilized extra dimensions in multidimensional gravitational
  models with nonlinear scalar curvature terms 1/R and R^4   We study multidimensional gravitational models with scalar curvature
nonlinearities of the type 1/R and R^4. It is assumed that the corresponding
higher dimensional spacetime manifolds undergo a spontaneous compactification
to manifolds with warped product structure. Special attention is paid to the
stability of the extra-dimensional factor spaces. It is shown that for certain
parameter regions the systems allow for a freezing stabilization of these
spaces. In particular, we find for the 1/R model that configurations with
stabilized extra dimensions do not provide a late-time acceleration (they are
AdS), whereas the solution branch which allows for accelerated expansion (the
dS branch) is incompatible with stabilized factor spaces. In the case of the
R^4 model, we obtain that the stability region in parameter space depends on
the total dimension D=dim(M) of the higher dimensional spacetime M. For D>8 the
stability region consists of a single (absolutely stable) sector which is
shielded from a conformal singularity (and an antigravity sector beyond it) by
a potential barrier of infinite height and width. This sector is smoothly
connected with the stability region of a curvature-linear model. For D<8 an
additional (metastable) sector exists which is separated from the conformal
singularity by a potential barrier of finite height and width so that systems
in this sector are prone to collapse into the conformal singularity. This
second sector is not smoothly connected with the first (absolutely stable) one.
Several limiting cases and the possibility for inflation are discussed for the
R^4 model.

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The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
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The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: supr-con
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The categories of this paper are: econ
9
The categories of this paper are: nlin
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The categories of this paper are: funct-an
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The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio