2009/10/31 by Nico Wintergerst, V. Pettorino, Valeria Pettorino +3 · 2 citations
Physics and Astronomy · #Astrophysics #Black Holes and Theoretical Physics #Cold dark matter #Cosmology #Cosmology and Gravitation Theories #Dark energy #Dark matter #Galaxies: Formation, Evolution, Phenomena #Neutrino #Particle physics #Physics #Quintessence #Universe #astro-ph.CO
paper · pdf · doi:10.1103/physrevd.81.063525
published as Phys.Rev.D81:063525,2010 · 17 pages, 16 figures, accepted for publication in Physical Review D, minor changes and corrections
arxiv created 2010/03/18 · openalex publication_date 2010/03/18 · arxiv updated 2010/04/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A quintessence scalar field or cosmon interacting with neutrinos can have important effects on cosmological structure formation. Within growing neutrino models the coupling becomes effective only in recent times, when neutrinos become nonrelativistic, stopping the evolution of the cosmon. This can explain why dark energy dominates the Universe only in a rather recent epoch by relating the present dark energy density to the small mass of neutrinos. Such models predict the presence of stable neutrino lumps at supercluster scales (\ensuremath∼200 Mpc and bigger), caused by an attractive force between neutrinos which is stronger than gravity and mediated by the cosmon. We present a method to follow the initial nonlinear formation of neutrino lumps in physical space, by integrating numerically on a 3D grid nonlinear evolution equations, until virialization naturally occurs. As a first application, we show results for cosmologies with final large neutrino average mass \ensuremath∼2 eV: in this case, neutrino lumps indeed form and mimic very large cold dark matter structures, with a typical gravitational potential 10^\ensuremath-5 for a lump size \ensuremath∼10 Mpc, and reaching larger values for lumps of about 200 Mpc. A rough estimate of the cosmological gravitational potential at small k in the nonlinear regime, \ensuremathΦ_\ensuremathν=10^\ensuremath-6(k/k0)^\ensuremath-2, 1.2\ifmmode×\else\texttimes\fi10^\ensuremath-2 h/Mpc<k0<7.8\ifmmode×\else\texttimes\fi10^\ensuremath-2 h/Mpc, turns out to be many orders of magnitude smaller than an extrapolation of the linear evolution of density fluctuations. The size of the neutrino-induced gravitational potential could modify the spectrum of CMB anisotropies for small angular momenta.