Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Counterexamples to the pseudo-Riemannian Lichnerowicz conjecture   The original version of the paper claimed to disprove the pseudo-Riemannian
Lichnerowicz conjecture of D'Ambra and Gromov. However, the argument contains a
crucial sign error in the lines following equation (8).

15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas