Cosmological constraints on quintessential halos
Abstract
A complex scalar field has recently been suggested to bind galaxies and flatten the rotation curves of spirals. Its cosmological behavior is thoroughly investigated here. Such a field is shown to be a potential candidate for the cosmological dark matter that fills up a fraction Omega_cdm = 0.3 of the Universe. However, problems arise when the limits from galactic dynamics and some cosmological constraints are taken simultaneously into account. A free complex field, associated to a very small mass m = 10^{-23} eV, has a correct cosmological behavior in the early Universe, but behaves today mostly as a real axion, with a problematic value of its conserved quantum number. On the other hand, an interacting field with quartic coupling lambda = 0.1 has a more realistic mass m = 1 eV and carries a quantum number close to the photon number density. Unlike a free field, it would be spinning today in the complex plane - like the so-called ``spintessence''. Unfortunately, the cosmological evolution of such field in the early Universe is hardly compatible with constraints from nucleosynthesis and structure formation.
Cite
@article{arxiv.astro-ph/0112324,
title = {Cosmological constraints on quintessential halos},
author = {Alexandre Arbey and Julien Lesgourgues and Pierre Salati},
journal= {arXiv preprint arXiv:astro-ph/0112324},
year = {2009}
}
Comments
13 pages, 3 figures. Some minor changes, version accepted in PRD