Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A uniqueness and regularity criterion for Q-tensor models with Neumann
  boundary conditions
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat