Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Almost Periodic Passive Tracer Dispersion   The authors investigate the impact of external sources on the pattern
formation of concentration profiles of passive tracers in a two-dimensional
shear flow. By using the pullback attractor technique for the associated
nonautonomous dynamical system, it is shown that a unique time-almost periodic
concentration profile exists for time-almost periodic external source.

21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics