Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tensor Perturbations and Thick Branes in Higher-dimensional $f(R)$
  Gravity   We study brane worlds in an anisotropic higher-dimensional spacetime within
the context of $f(R)$ gravity. Firstly, we demonstrate that this spacetime with
a concrete metric ansatz is stable against linear tensor perturbations under
certain conditions. Moreover, the Kaluza-Klein modes of the graviton are
analyzed. Secondly, we investigate thick brane solutions in six dimensions and
their properties. We further exhibit two sets of solutions for thick branes. At
last, the effective potential of the Kaluza-Klein modes of the graviton is
discussed for the two solved $f(R)$ models in higher dimensions.

20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ