Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Large-Scale Flow and Spiral Core Instability in Rayleigh-Benard
  Convection   The spiral core instability, observed in large aspect ratio Rayleigh-Benard
convection, is studied numerically in the framework of the Swift-Hohenberg
equation coupled to a large-scale flow. It is shown that the instability leads
to non-trivial core dynamics and is driven by the self-generated vorticity.
Moreover, the recently reported transition from spirals to hexagons near the
core is shown to occur only in the presence of a non-variational nonlinearity,
and is triggered by the spiral core instability. Qualitative agreement between
the simulations and the experiments is demonstrated.

35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
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
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat