Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cohomological invariants and the classifying space for proper actions   We investigate two open questions in a cohomology theory relative to the
family of finite subgroups. The problem of whether the F-cohomological
dimension is subadditive is reduced to extensions by groups of prime order. We
show that every finitely generated regular branch group has infinite rational
cohomological dimension. Moreover, we prove that the first Grigorchuk group G
is not contained in Kropholler's class HF .

17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an