Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Singularities in string theory   String theory is a quantum theory that reproduces the results of General
Relativity at long distances but is completely different at short distances.
Mathematically, string theory is based on a very new -- and little understood
-- framework for geometry that reduces to ordinary differential geometry when
the curvature is asymptotically small. In the 1990's, many interesting results
were obtained about the behavior of string theory in spacetimes that develop
singularities. In many cases, the physics at the singularity is governed by an
effective Lagrangian constructed using an interesting bit of classical geometry
such as the association of A-D-E groups with certain hypersurface singularities
or the ADHM construction of instantons. In other examples, the physics at the
singularity cannot be described in classical terms but involves a non-Gaussian
conformal field theory.

9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
19
The categories of this paper are: eess
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th