Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The impact of Early Dark Energy on non-linear structure formation   We study non-linear structure formation in high-resolution simulations of
Early Dark Energy (EDE) cosmologies and compare their evolution with the
standard LCDM model. Extensions of the spherical top-hat collapse model predict
that the virial overdensity and linear threshold density for collapse should be
modified in EDE model, yielding significant modifications in the expected halo
mass function. Here we present numerical simulations that directly test these
expectations. Interestingly, we find that the Sheth & Tormen formalism for
estimating the abundance of dark matter halos continues to work very well in
its standard form for the Early Dark Energy cosmologies, contrary to analytic
predictions. The residuals are even slightly smaller than for LCDM. We also
study the virial relationship between mass and dark matter velocity dispersion
in different dark energy cosmologies, finding excellent agreement with the
normalization for Lambda as calibrated by Evrard et al.(2008). The earlier
growth of structure in EDE models relative to LCDM produces large differences
in the mass functions at high redshift. This could be measured directly by
counting groups as a function of the line-of-sight velocity dispersion,
skirting the ambiguous problem of assigning a mass to the halo. Using dark
matter substructures as a proxy for member galaxies, we demonstrate that even
with 3-5 members sufficiently accurate measurements of the halo velocity
dispersion function are possible. Finally, we determine the concentration-mass
relationship for our EDE cosmologies. Consistent with the earlier formation
time, the EDE halos show higher concentrations at a given halo mass. We find
that the magnitude of the difference in concentration is well described by the
prescription of Eke et al.(2001) for estimating halo concentrations.

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The categories of this paper are: nucl-th
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The categories of this paper are: quant-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ex
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The categories of this paper are: stat
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The categories of this paper are: math
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The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
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The categories of this paper are: comp-gas
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The categories of this paper are: mtrl-th
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The categories of this paper are: solv-int
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The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: econ
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The categories of this paper are: adap-org