Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An integral formula for the $Q$-prime curvature in 3-dimensional CR
  geometry   We give an integral formula for the total $Q^\prime$-curvature of a
three-dimensional CR manifold with positive CR Yamabe constant and nonnegative
Paneitz operator. Our derivation includes a relationship between the Green's
functions of the CR Laplacian and the $P^\prime$-operator.

4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga