Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Krein space related perturbation theory for MHD alpha-2-dynamos and
  resonant unfolding of diabolical points   The spectrum of the spherically symmetric alpha-2 dynamo is studied in the
case of idealized boundary conditions. Starting from the exact analytical
solutions of models with constant alpha-profiles a perturbation theory and a
Galerkin technique are developed in a Krein-space approach. With the help of
these tools a very pronounced alpha-resonance pattern is found in the
deformations of the spectral mesh as well as in the unfolding of the diabolical
points located at the nodes of this mesh. Non-oscillatory as well as
oscillatory dynamo regimes are obtained. A Fourier component based estimation
technique is developed for obtaining the critical alpha-profiles at which the
eigenvalues enter the right spectral half-plane with non-vanishing imaginary
components (at which overcritical oscillatory dynamo regimes form). Finally,
Frechet derivative (gradient) based methods are developed, suitable for further
numerical investigations of Krein-space related setups like MHD alpha-2-dynamos
or models of PT-symmetric quantum mechanics.

4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom