Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Extra States in C<1 String Theory   A construction of elements of the BRS cohomology of ghost number +/- 1 in c<1
string theory is described, and their two-point function computed on the
sphere. The construction makes precise the relation between these extra states
and null vectors. The physical states of ghost number +1 are found to be exact
forms with respect to a ``conjugate'' BRS operator.

23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs