Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: G\"{o}del-type universes in bumblebee gravity   The bumblebee field coupled with gravity is considered. This gravitational
theory exhibits spontaneous breaking of Lorentz symmetry. The G\"{o}del-type
universe is introduced and then the causality and its violation are studied.
Causal and non-causal G\"{o}del-type solutions are obtained for different
content of matter. In addition, when the coupling constant, which controls the
interaction between the bumblebee field and the gravitational field, is zero
the bumblebee potential may be associated with the value of the cosmological
constant of the general relativity. Furthermore, the case with the non-zero
coupling constant is also investigated.

12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
18
The categories of this paper are: econ