Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Real representations of semisimple Lie algebras have Q-forms   We prove that each real semisimple Lie algebra G has a Q-form, such that
every real representation of G can be realized over the rational numbers Q.
This was previously proved by M.S.Raghunathan (and rediscovered by P.Eberlein)
in the special case where G is compact.

13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th