Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Closed hypersurfaces of low entropy in $\mathbb{R}^4$ are isotopically
  trivial   We show that any closed connected hypersurface in $\mathbb{R}^4$ with entropy
less than or equal to that of the round cylinder is smoothly isotopic to the
standard three-sphere.

31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ