Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Stability of Homogeneous Extra Dimensions   In order not to be in conflict with observations it is crucial that extra
dimensions, if they exist, are stable. It is shown that in the context of
homogeneous extra dimensions, this can easily be achieved during both (4D)
radiation and vacuum energy dominated eras of the cosmological evolution.
During matter domination, however, there is no such possibility even for a very
general class of stabilization mechanisms. Even if extra dimensions could be
stabilized during matter domination, it is argued that they are generically
time-varying during any transition period, such as the one from radiation to
matter domination.

18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol