2006/09/19 by A. Gruzinov, Andrei Gruzinov, Matthew Kleban +5 · 2 citations
Physics and Astronomy · #Anisotropy #Astrophysics #Black Holes and Theoretical Physics #Classical mechanics #Cosmological perturbation theory #Cosmology #Cosmology and Gravitation Theories #Dark energy #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gravitation #Hubble's law #Physics #Quantum mechanics #Scale (ratio) #Structure formation #Theoretical physics #Universe #astro-ph #hep-th
paper · pdf · doi:10.1088/1475-7516/2006/12/001
published as JCAP0612:001,2006 · 16 pages
arxiv created 2006/09/19 · openalex publication_date 2006/12/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The non-linearity of Einstein's equations makes it possible for small scale matter inhomogeneities to affect the universe at cosmological distances. We study the size of such effects using a simple heuristic model that captures the most important backreaction effect due to non-relativistic matter, as well as several exact solutions describing inhomogeneous and anisotropic expanding universes. We find that the effects are O( H 2 l 2 / c 2 ) or smaller, where H is the Hubble parameter and l the typical size scale of inhomogeneities. For virialized structures this is of order v 2 / c 2 , where v is the characteristic peculiar velocity.