Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Recent Dynamical Relaxation of Galaxy Clusters: Evidence for a
  Low-$\Omega_m$ Universe   We argue that there has been substantial evolution in the ellipticity of rich
galaxy clusters between 0 < z < 0.1, and suggest that this is additional
evidence for a low matter-density Universe.

18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an