Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-convergence of the critical cooling timescale for fragmentation of
  self-gravitating discs   We carry out a resolution study on the fragmentation boundary of
self-gravitating discs. We perform three-dimensional Smoothed Particle
Hydrodynamics simulations of discs to determine whether the critical value of
the cooling timescale in units of the orbital timescale, beta_{crit}, converges
with increasing resolution. Using particle numbers ranging from 31,250 to 16
million (the highest resolution simulations to date) we do not find
convergence. Instead, fragmentation occurs for longer cooling timescales as the
resolution is increased. These results suggest that at the very least, the
critical value of the cooling timescale is longer than previously thought.
However, the absence of convergence also raises the question of whether or not
a critical value exists. In light of these results, we caution against using
cooling timescale or gravitational stress arguments to deduce whether
gravitational instability may or may not have been the formation mechanism for
observed planetary systems.

32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph