Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Recent Developments in String Theory: From Perturbative Dualities to
  M-Theory   These lectures intend to give a pedagogical introduction into some of the
developments in string theory during the last years. They include perturbative
T-duality and non perturbative S- and U-dualities, their unavoidable demand for
D-branes, an example of enhanced gauge symmetry at fixed points of the
T-duality group, a review of classical solitonic solutions in general
relativity, gauge theories and tendimensional supergravity, a discussion of
their BPS nature, Polchinski's observations that allow to view D-branes as RR
charged states in the non perturbative string spectrum, the application of all
this to the computation of the black hole entropy and Hawking radiation and
finally a brief survey of how everything fits together in M-theory.

27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
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The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con