Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Anisotropic Extra Dimensions   We consider the scenario where in a five-dimensional theory, the extra
spatial dimension has different scaling than the other four dimensions. We find
background maximally symmetric solutions, when the bulk is filled with a
cosmological constant and at the same time it has a three-brane embedded in it.
These background solutions are reminiscent of Randall-Sundrum warped metrics,
with bulk curvature depending on the parameters of the breaking of
diffeomorphism invariance. Subsequently, we consider the scalar perturbation
sector of the theory and show that it has certain pathologies and the striking
feature that in the limit where the diffeomorphism invariance is restored,
there remain ghost scalar mode(s) in the spectrum.

22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con