Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Long-lived lop-sided modes of annular disks orbiting a central mass   We demonstrate the existence of long-lived, large-amplitude eccentric modes
in massive, annular particle disks in orbit about a central mass. The lopsided
modes we have found precess slowly in the prograde direction at a rate which
increases with disk mass and decreases with the amplitude of the distortion.
The lopsidedness generally survives for as long as we run the calculations and
may last indefinitely; we found no significant decay in over 700 disk-particle
orbits in one case. These strongly non-linear modes are readily created using a
number of different perturbing rules, but we find no evidence for linear
instabilities in unperturbed disks. Our results suggest that Tremaine's
eccentric disk model for the nucleus of M31 may be viable, but none of our
models matches all aspects of the observational data.

18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex