Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lattices and Cohomology   We give an interpretation of the cohomology of an arithmetically defined
group as a set of equivalence classes of lattices. We use this interpretation
to give a simpler proof of the connection established by J. Rohlfs between
genus and cohomology.

32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con