Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lyra black holes   Long ago, since 1951, Lyra proposed a modification of Riemannian geometry.
Based on the Lyra's modification on Riemannian geometry, Sen and Dunn
constructed a field equation which is analogous to Einstein's field equations.
Further more, Sen and Dunn gave series type solution to the static vacuum field
equations. Retaining only a few terms, we have shown that their solutions
correspond to black holes (we call, Lyra black holes). Some interesting
properties of the Lyra black holes are studied.

37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th