Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Field-induced phases of an orientable charged particle in a dilute
  background of point charges   We study a dynamical model of a rod-like particle surrounded by a cloud of
smaller particles of the same charge and we show that, in the presence of a
low-frequency alternating electric field, the rod displays the same type of
anomalous orientation (perpendicular to the field) that was recently observed
in laboratory colloids. This indicates that the anomalous orientation is due to
the collective dynamics of the colloidal particles, and does not require
electro-osmotic effects. We also confirm the experimental observation that for
higher field frequencies the standard orientation (parallel to the field)
prevails. In the simulations, these changes are abrupt enough to resemble a
phase transition.

23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math