Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The conformal group of a compact simply connected Lorentzian manifold   We prove that the conformal group of a closed, simply connected, real
analytic Lorentzian manifold is compact. D'Ambra proved in 1988 that the
isometry group of such a manifold is compact. Our result implies the Lorentzian
Lichnerowicz Conjecture for real analytic Lorentzian manifolds with finite
fundamental group.
  Third version includes corrections and clarifications, particularly in
section 6.

36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
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The categories of this paper are: alg-geom
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The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con