Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Scalar cosmological perturbation in an inflationary brane world driven
  by the bulk inflaton   We investigate scalar perturbations from inflation in a bulk inflaton
braneworld model. Using the generalized longitudinal gauge, we derive and solve
the full set of scalar perturbation equations. Our exact results support the
recent argument that for the de Sitter brane the square of the radion mass is
not positive, showing that unlike the flat brane case, the de Sitter brane is
not stable.

28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol