Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On a Cahn-Hilliard type phase field system related to tumor growth   The paper deals with a phase field system of Cahn-Hilliard type. For positive
viscosity coefficients, the authors prove an existence and uniqueness result
and study the long time behavior of the solution by assuming the nonlinearities
to be rather general. In a more restricted setting, the limit as the viscosity
coefficients tend to zero is investigated as well.

27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an