Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Consideration of the relationship between Kepler and cyclotron dynamics
  leading to prediction of a non-MHD gravity-driven Hamiltonian dynamo   Conservation of canonical angular momentum shows that charged particles are
typically constrained to stay within a poloidal Larmor radius of a poloidal
magnetic flux surface. However, more detailed consideration shows that
particles with a critical charge to mass ratio can have zero canonical angular
momentum and so be both immune from centrifugal force and not constrained to
stay in the vicinity of a specific flux surface. Suitably charged dust grains
can have zero canonical angular momentum and in the presence of a gravitational
field will spiral inwards across poloidal magnetic surfaces toward the central
object and accumulate. This accumulation results in a gravitationally-driven
dynamo, i.e., a mechanism for converting gravitational potential energy into a
battery-like electric power source.

9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph