Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Open Strings in a B-field Background as Electric Dipoles   Studying dynamics of open strings attached to a D2-brane in a NS two form
field background, we find that these open strings act as dipoles of U(1) gauge
field of the brane. This provides an string theoretic description of the flux
modifications needed for the DBI action on noncommutative torus.

23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc