Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Polyakov conjecture and 2+1 dimensional gravity   After briefly reviewing the hamiltonian approach to 2+1 dimensional gravity
in absence of matter on closed universes, we consider 2+1 dimensional gravity
coupled to point particles in an open universe. We show that the hamiltonian
structure of the theory is the result of a conjecture put forward by Polyakov
in a different context. A proof is given of such a conjecture. Finally we give
the exact quantization of the two particle problem in open space.

1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph