Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Squashed Kerr-Godel Black Holes - Kaluza-Klein Black Holes with
  Rotations of Black Hole and Universe -   Applying squashing transformation to Kerr-Godel black hole solutions, we
present a new type of a rotating Kaluza-Klein black hole solution to the
five-dimensional Einstein-Maxwell theory with a Chern-Simon term. The new
solutions generated via the squashing transformation have no closed timelike
curve everywhere outside the black hole horizons. At the infinity, the metric
asymptotically approaches a twisted S^1 bundle over a four-dimensional
Minkowski space-time. One of the remarkable features is that the solution has
two independent rotation parameters along an extra dimension associated with
the black hole's rotation and the Godel's rotation. The space-time also admits
the existence of two disconnected ergoregions, an inner ergoregion and an outer
ergoregion. These two ergoregions can rotate in the opposite direction as well
as in the same direction.

25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph