Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Extremals for the Sobolev inequality on the seven dimensional
  quaternionic Heisenberg group and the quaternionic contact Yamabe problem   A complete solution to the quaternionic contact Yamabe problem on the seven
dimensional sphere is given. Extremals for the Sobolev inequality on the seven
dimensional Hesenberg group are explicitly described and the best constant in
the $L^2$ Folland-Stein embedding theorem is determined.

36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess