Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Stability of the GRS Model   We discuss the compatibility between the weaker energy condition and the
stability of Gregory, Rubakov and Sibiryakov (GRS) model. Because the GRS
spacetime violates the weak energy condition, it may cause the instability. In
the GRS model, the four dimensional gravity can be described by the massive KK
modes with the resonance. Hence, instead of considering the weaker energy
condition, we require for the stability of this model: no tachyon and no ghost
condition for graviton modes ($h_{\mu\nu}$). No tachyonic condition ($m^2_h
\geq 0$) is satisfied because the lowest state $m_h=0$ is supersymmetric vacuum
state. Further, no ghost state condition is achieved if one requires some
relations for the matter source: $2T_{55}= T^{\mu}_{\mu}=3(T_{22}+T_{33})$. It
turns out that, although the GRS spacetime does not satisfy the weaker energy
condition, it is stable against small perturbation.

23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom