Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Parallel spinors and connections with skew-symmetric torsion in string
  theory   We describe all almost contact metric, almost hermitian and $G_2$-structures
admitting a connection with totally skew-symmetric torsion tensor, and prove
that there exists at most one such connection. We investigate its torsion form,
its Ricci tensor, the Dirac operator and the $\nabla$-parallel spinors. In
particular, we obtain solutions of the type II string in dimension $n=5,6$ and
7.

28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an