Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Half-flat nilmanifolds   We introduce a double complex that can be associated to certain Lie algebras,
and show that its cohomology determines an obstruction to the existence of a
half-flat SU(3)-structure. We obtain a classification of the 6-dimensional
nilmanifolds carrying an invariant half-flat structure.

24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom