Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: D-Branes And K-Theory   By exploiting recent arguments about stable nonsupersymmetric D-brane states,
we argue that D-brane charge takes values in the K-theory of spacetime, as has
been suspected before. In the process, we gain a new understanding of some
novel objects proposed recently - such as the Type I zerobrane - and we
describe some new objects - such as a -1-brane in Type I superstring theory.

26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int