Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Conformal field theory, boundary conditions and applications to string
  theory   This is an introduction to two-dimensional conformal field theory and its
applications in string theory. Modern concepts of conformal field theory are
explained, and it is outlined how they are used in recent studies of D-branes
in the strong curvature regime by means of CFT on surfaces with boundary.

1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat