Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Search for non-helical disc dynamos in simulations   The possibility of non-helical large scale dynamo action is investigated
using three-dimensional simulations of global accretion discs as well as
idealized local simulations without rotation and only shear. Particular
emphasis is placed on a certain correlation between vorticity and azimuthal
velocity gradient which has been predicted to drive large scale dynamo action,
independent of the presence or absence of kinetic helicity. In the global disc
simulations two types of behaviours are found: those which do show this type of
velocity correlation and those which do not. The former ones are typically also
the cases where the resistivity is larger. The latter ones show signs typical
of dynamo action based on the usual helicity effect. In the idealized
simulations without rotation and just shear the above correlation is found to
be particularly strong. In both cases there is, as expected, a systematic flux
of magnetic helicity through the midplane. However, very little helicity flux
leaves the domain through the top and bottom boundaries. The idealized
simulations reveal that much of this systematic flux comes from the rotational
component of the helicity flux and does not contribute to its divergence.

10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci