Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cosmological Effects of Radion Oscillations   We show that the redshift of pressureless matter density due to the expansion
of the universe generically induces small oscillations in the stabilized radius
of extra dimensions (the radion field). The frequency of these oscillations is
proportional to the mass of the radion and can have interesting cosmological
consequences. For very low radion masses $m_b$ ($m_b\sim10-100
H_0\simeq10^{-32} eV$) these low frequency oscillations lead to oscillations in
the expansion rate of the universe. The occurrence of acceleration periods
could naturally lead to a resolution of the coincidence problem, without need
of dark energy. Even though this scenario for low radion mass is consistent
with several observational tests it has difficulty to meet fifth force
constraints. If viewed as an effective Brans-Dicke theory it predicts
$\omega=-1+\frac{1}{D}$ ($D$ is the number of extra dimensions), while
experiments on scales larger than $1mm$ imply $\omega>2500$. By deriving the
generalized Newtonian potential corresponding to a massive toroidally compact
radion we demonstrate that Newtonian gravity is modified only on scales smaller
than $m_b^{-1}$. Thus, these constraints do not apply for $m_b>10^{-3} eV$
(high frequency oscillations) corresponding to scales less than the current
experiments ($0.3mm$). Even though these high frequency oscillations can not
resolve the coincidence problem they provide a natural mechanism for dark
matter generation. This type of dark matter has many similarities with the
axion.

34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph