Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sign-changing tower of bubbles for the Brezis-Nirenberg problem   In this paper, we prove that the Brezis-Nirenberg problem -\Delta u =
|u|^{p-1}u+\epsilon u in \Omega; u=0 on \partial \Omega where \Omega is a
symmetric bounded smooth domain in R^N, N\geq 7 and p = (N+2)/(N-2), has a
solution with the shape of a tower of two bubbles with alternate signs,
centered at the center of symmetry of the domain, for all \epsilon > 0
sufficiently small.

10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int