Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: T-dual-coordinate dependence makes the effective Kalb-Ramond field
  nontrivial   We show that the fact that the string theory is unoriented does not
necessarily force the Kalb-Ramond field to vanish. We investigated the theory
of the open string propagating in the weakly curved background. The effective
Kalb-Ramond field $B^{eff}_{\mu\nu}$, the background field of the effective
theory obtained on the solution of the boundary conditions, does not depend on
the $\Omega$-even effective coordinate $q$, but on its T-dual $\tilde{q}$ which
is $\Omega$-odd. This brakes the standard proof that the term with
$B_{\mu\nu}^{eff}$ should vanish. From the world-sheet equations of motion we
identify $B_{\mu\nu}^{eff}$ with the torsion potential.

28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con