Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Problems with kinematic mean field electrodynamics at high magnetic
  Reynolds numbers   We discuss the applicability of the kinematic $\alpha$-effect formalism at
high magnetic Reynolds numbers. In this regime the underlying flow is likely to
be a small-scale dynamo, leading to the exponential growth of fluctuations.
Difficulties arise with both the actual calculation of the $\alpha$
coefficients and with its interpretation. We argue that although the former may
be circumvented -- and we outline several procedures by which the the $\alpha$
coefficients can be computed in principle -- the interpretation of these
quantities in terms of the evolution of the large-scale field may be
fundamentally flawed.

21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an