Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The structure of the pro-l-unipotent fundamental group of a smooth
  variety   By developing a theory of deformations over nilpotent Lie algebras, based on
Schlessinger's deformation theory over Artinian rings, this paper investigates
the pro-l-unipotent fundamental group of a variety X. If X is smooth and
proper, defined over a finite field, then the Weil conjectures imply that this
group is quadratically presented. If X is smooth and non-proper, then the group
is defined by equations of bracket length at most four.

16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th