Modeling the phase-space distribution around massive halos

2013/05/23 by Tsz Yan Lam, Fabian Schmidt, Takahiro Nishimichi +1 · 29 citations
Mathematics · Physics and Astronomy · #Astrophysics #Black Holes and Theoretical Physics #Classical mechanics #Computer science #Cosmology and Gravitation Theories #Dispersion (optics) #Distribution (mathematics) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Line-of-sight #Mass distribution #Mathematical analysis #Mathematics #Optics #Phase space #Physics #Quantum mechanics #Space (punctuation) #Velocity dispersion #Virial theorem #astro-ph.CO

paper · pdf · doi:10.1103/physrevd.88.023012

published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 88(2) (American Physical Society) · 27 pages, 18 figures. To be submitted

arxiv created 2013/05/23 · openalex publication_date 2013/07/26 · arxiv updated 2013/08/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

The comparison between dynamical mass and lensing mass provides a targeted test for a wide range of modified gravity models. In our previous paper Lam et al. [Phys. Rev. Lett. 109, 051301 (2012)] we showed, through numerical simulations, that the measurement of the line-of-sight velocity dispersion around stacked massive clusters whose lensing masses are known allows for stringent constraints on modified gravity on scales of 2--15h^\ensuremath-1 Mpc. In this work we develop a semianalytical approach based on the halo model to describe the phase-space distribution and the line-of-sight velocity dispersion for different tracers. The model distinguishes contributions from the halo pairwise velocity and the virial velocity within halos. We also discuss observational complications, in particular the contribution from Hubble flow, and show how our model can incorporate these complications. We then incorporate the effects of modified gravity [specifically, f(R) and braneworld models], and show that the model predictions are in excellent agreement with modified gravity simulations. More broadly, the phase-space distribution provides a sensitive test of our understanding of hierarchical structure formation when confronted with observations via this model.

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