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Title: Dark Energy and The Dark Matter Relic Abundance

Abstract

Two mechanisms by which the quintessence scalar could enhance the relic abundance of dark matter particles are discussed. These effects can have an impact on supersymmetric candidates for dark matter.

Authors:
 [1];  [2]
  1. Universita di Padova, Dipartimento di Fisica 'Galileo Galilei', via Marzolo 8, 35131 Padova (Italy)
  2. (Italy)
Publication Date:
OSTI Identifier:
20630322
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 736; Journal Issue: 1; Conference: Conference on phi in the sky: The quest for cosmological scalar fields, Porto (Portugal), 8-10 Jul 2004; Other Information: DOI: 10.1063/1.1835185; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ABUNDANCE; NONLUMINOUS MATTER; SCALARS; SPARTICLES; SUPERSYMMETRY

Citation Formats

Rosati, Francesca, and INFN - Sezione di Padova, via Marzolo 8, 35131 Padova. Dark Energy and The Dark Matter Relic Abundance. United States: N. p., 2004. Web. doi:10.1063/1.1835185.
Rosati, Francesca, & INFN - Sezione di Padova, via Marzolo 8, 35131 Padova. Dark Energy and The Dark Matter Relic Abundance. United States. doi:10.1063/1.1835185.
Rosati, Francesca, and INFN - Sezione di Padova, via Marzolo 8, 35131 Padova. 2004. "Dark Energy and The Dark Matter Relic Abundance". United States. doi:10.1063/1.1835185.
@article{osti_20630322,
title = {Dark Energy and The Dark Matter Relic Abundance},
author = {Rosati, Francesca and INFN - Sezione di Padova, via Marzolo 8, 35131 Padova},
abstractNote = {Two mechanisms by which the quintessence scalar could enhance the relic abundance of dark matter particles are discussed. These effects can have an impact on supersymmetric candidates for dark matter.},
doi = {10.1063/1.1835185},
journal = {AIP Conference Proceedings},
number = 1,
volume = 736,
place = {United States},
year = 2004,
month =
}
  • Scalar-tensor theories of gravity provide a consistent framework to accommodate an ultralight quintessence scalar field. While the equivalence principle is respected by construction, deviations from general relativity and standard cosmology may show up at nucleosynthesis, cosmic microwave background, and solar system tests of gravity. After imposing all the bounds coming from these observations, we consider the expansion rate of the Universe at weakly interacting massive particle decoupling, showing that it can lead to an enhancement of the dark matter relic density up to few orders of magnitude with respect to the standard case. This effect can have an impact onmore » supersymmetric candidates for dark matter.« less
  • Neutralino annihilation and elastic scattering cross sections are derived which differ in important ways from previous work. These are applied to relic abundance calculations and to direct detection of neutralino dark matter from the galactic halo. Assuming the neutralino is the lightest supersymmetric particle and that it is less massive than the Z/sup 0/, we find relic densities of neutralinos greater than 4% of critical density for almost all values of the supersymmetric parameters. We constrain the parameter space by using results from the DESY e/sup +/e/sup -/ storage ring PETRA (chargino mass less than 23 GeV) and the ASPmore » detector at the SLAC storage ring PEP, and then assuming a critical density of neutralinos, display event rates in a cryogenic detector for a variety of models. A new term implies ''spin-independent'' elastic scattering even for these Majorana particles and inclusion of propagator momenta increases detection rates by 10--300 % even for pure photinos. Z/sup 0/-squark interference leads to very low detection rates for some values of the parameters. The new term in the elastic cross section dominates for heavy, mostly spinless materials and mitigates the negative interference cancellations in light materials, except for the pure photino or pure Higgsino cases where it does not contribute. In general, the rates can be substantially different from the pure photino and pure Higgsino special cases usually considered.« less
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  • We analyze thermal relic abundance of neutralino dark matter and discuss future prospects of its direct and indirect detections in mirage mediation.
  • Relic abundance of dark matter is investigated in the framework of universal extra dimension models with right-handed neutrinos. These models are free from the serious Kaluza-Klein (KK) graviton problem that the original universal extra dimension model has. The first KK particle of the right-handed neutrino is a candidate for dark matter in this framework, and its relic abundance is determined by three processes, (1) the decay of the KK photon into the first KK right-handed neutrino in the late universe, (2) production of the first KK right-handed neutrino from the thermal bath in the early universe, and (3) the decaymore » of higher KK right-handed neutrinos into the first KK right-handed neutrino in the late universe. When ordinary neutrino masses are large enough such as the degenerate mass spectrum case, the last process contributes to the abundance significantly, even if the reheating temperature is low. The scale of the extra dimension consistent with cosmological observations can be 500 GeV in the minimal setup of universal extra dimension models with right-handed neutrinos.« less