Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cosmological Perturbations in Extended Massive Gravity   We study cosmological perturbations around self-accelerating solutions to two
extensions of nonlinear massive gravity: the quasi-dilaton theory and the
mass-varying theory. We examine stability of the cosmological solutions, and
the extent to which the vanishing of the kinetic terms for scalar and vector
perturbations of self-accelerating solutions in massive gravity is generic when
the theory is extended. We find that these kinetic terms are in general
non-vanishing in both extensions, though there are constraints on the
parameters and background evolution from demanding that they have the correct
sign. In particular, the self-accelerating solutions of the quasi-dilaton
theory are always unstable to scalar perturbations with wavelength shorter than
the Hubble length.

18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat