Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Long time localization of modified surface quasi-geostrophic equations   We discuss the time evolution of a two-dimensional active scalar flow, which
extends some properties valid for a two-dimensional incompressible nonviscous
fluid. In particular we study some characteristics of the dynamics when the
field is initially concentrated in $N$ small disjoint regions, and we discuss
the conservation in time of this localization property. We discuss also how
long this localization persists, showing that in some cases this happens for
quite long times.

28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
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The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th