Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Mass-To-Light Function: Antibias and Omega_m   We use large-scale cosmological simulations to estimate the mass-to-light
ratio of galaxy systems as a function of scale, and compare the results with
observations of galaxies, groups, clusters, and superclusters of galaxies. We
find remarkably good agreement between observations and simulations.
Specifically, we find that the simulated mass-to-light ratio increases with
scale on small scales and flattens to a constant value on large scales, as
suggested by observations. We find that while mass typically follows light on
large scales, high overdensity regions --- such as rich clusters and
superclusters of galaxies --- exhibit higher M/L_B values than average, while
low density regions exhibit lower M/L_B values; high density regions are thus
antibiased in M/L_B, with mass more strongly concentrated than blue light. This
is true despite the fact that the galaxy mass density is unbiased or positively
biased relative to the total mass density in these regions. The M/L_B antibias
is likely due to the relatively old age of the high density regions, where
light has declined significantly since their early formation time, especially
in the blue band which traces recent star formation. Comparing the simulated
results with observations, we place a powerful constraint on the mass density
of the universe; using, for the first time, the entire observed mass-to-light
function, from galaxies to superclusters, we find Omega =0.16+/-0.05.

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The categories of this paper are: hep-lat
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The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
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The categories of this paper are: eess
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The categories of this paper are: alg-geom
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The categories of this paper are: econ
25
The categories of this paper are: patt-sol
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The categories of this paper are: mtrl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: atom-ph
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The categories of this paper are: math
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The categories of this paper are: plasm-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: math-ph