Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mirror Images of String Cosmologies   A discrete symmetry of the four-dimensional string effective action is
employed to derive spatially homogeneous and inhomogeneous string cosmologies
from vacuum solutions of general relativity that admit two commuting spacelike
Killing vectors. In particular, a tilted Bianchi type V cosmology is generated
from a vacuum type VI_h solution and a plane wave solution with a bounded and
oscillating dilaton field is found from a type ${\rm VII}_h$ model. Further
applications are briefly discussed.

37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an