Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Recent Dynamical Evolution of Galaxy Clusters   Evidence is presented for a recent evolution of the relaxation processes in
clusters of galaxies, using large optical and X-ray cluster samples. The
criteria of the cluster relaxation used are the cluster ellipticity, the ICM
temperature and X-ray cluster luminosity. We find evidence of varying strength
and significance of all three indicators evolving with redshift for z <0.15.
This result supports the view that clusters have mostly stopped undergoing
mergers and accreting matter, as expected in a low-Omega_matter Universe, and
are now in the process of gravitational relaxation, which reduces their
flattening, their ICM temperature (shock heated during the merging phase), and
their X-ray luminosity. These results support similar recent claims of Melott,
Chambers and Miller (2001).

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The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
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The categories of this paper are: cmp-lg
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The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
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The categories of this paper are: funct-an
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The categories of this paper are: q-fin
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The categories of this paper are: bayes-an
3
The categories of this paper are: physics
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The categories of this paper are: q-bio
2
The categories of this paper are: math