Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Positive solutions of some parabolic system with cross-diffusion and
  nonlocal initial conditions   The paper is concerned with a system consisting of two coupled nonlinear
parabolic equations with a cross-diffusion term, where the solutions at
positive times define the initial states. The equations arise as steady state
equations of an age-structured predator-prey system with spatial dispersion.
Based on unilateral global bifurcation methods for Fredholm operators and on
maximal regularity for parabolic equations, global bifurcation of positive
solutions is derived.

3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg