Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Einstein static universe with torsion and the sign problem of the
  cosmological constant   In the field equations of Einstein-Cartan theory with cosmological constant a
static spherically symmetric perfect fluid with spin density satisfying the
Weyssenhoff restriction is considered. This serves as a rough model of space
filled with (fermionic) dark matter. From this the Einstein static universe
with constant torsion is constructed, generalising the Einstein Cosmos to
Einstein-Cartan theory.
  The interplay between torsion and the cosmological constant is discussed. A
possible way out of the cosmological constant's sign problem is suggested.

24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int