Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Relative structure cycles and the existence of smooth Lyapunov 1-forms
  for flows   We give necessary and sufficient conditions for the existence of smooth
Lyapunov 1-forms for the flow of a smooth vector field in terms of the behavior
of certain locally finite invariant measures. The main statement generalizes a
result of Schwartzman, whereas the methods are adapted from work of Sullivan.

14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
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The categories of this paper are: q-fin
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The categories of this paper are: stat
30
The categories of this paper are: q-alg
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The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex