Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Statistical State Dynamics: a new perspective on turbulence in shear
  flow   Traditionally, single realizations of the turbulent state have been the
object of study in shear flow turbulence. When a statistical quantity was
needed it was obtained from a spatial, temporal or ensemble average of sample
realizations of the turbulence. However, there are important advantages to
studying the dynamics of the statistical state (the SSD) directly. In highly
chaotic systems statistical quantities are often the most useful and the
advantage of obtaining these statistics directly from a state variable is
obvious. Moreover, quantities such as the probability density function (pdf)
are often difficult to obtain accurately by sampling state trajectories even if
the pdf is stationary. In the event that the pdf is time dependent, solving
directly for the pdf as a state variable is the only alternative. However,
perhaps the greatest advantage of the SSD approach is conceptual: adopting this
perspective reveals directly the essential cooperative mechanisms among the
disparate spatial and temporal scales that underly the turbulent state. While
these cooperative mechanisms have distinct manifestation in the dynamics of
realizations of turbulence both these cooperative mechanisms and the phenomena
associated with them are not amenable to analysis directly through study of
realizations as they are through the study of the associated SSD. In this
review a selection of example problems in the turbulence of planetary and
laboratory flows is examined using recently developed SSD analysis methods in
order to illustrate the utility of this approach to the study of turbulence in
shear flow.

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The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con