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arXiv · astro-ph/9812387

Dynamics of pairwise motions

Roman Juszkiewicz·Volker Springel·Ruth Durrer
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Abstract

We derive a simple closed-form expression, relating $\vs(r)$ -- the mean relative velocity of pairs of galaxies at fixed separation $r$ -- to the two-point correlation function of mass density fluctuations, $ξ(r)$. We compare our analytic model for $\vs(r)$ with N-body simulations, and find excellent agreement in the entire dynamical range probed by the simulations ($0.1 \lsim ξ\lsim 1000$). Our results can be used to estimate the cosmological density parameter, $\Om$, directly from redshift-distance surveys, like Mark III.

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Roman Juszkiewicz, Volker Springel, Ruth Durrer. 1998-12-21. Dynamics of pairwise motions. https://doi.org/10.1086/312055

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