Isocurvature bounds on axions revisited
Abstract
The axion is one of the best motivated candidates for particle dark matter. We study and update the constraints imposed by the recent CMB and LSS experiments on the mass of axions produced by the misalignment mechanism, as a function of both the inflationary scale and the reheating temperature. Under some particular although not unconventional assumptions, the axion induces isocurvature perturbations with an amplitude too large to be compatible with observations. Specifically, for inflation taking place at intermediate energy scales, we derive some restrictive limits which can only be evaded by assuming an efficient reheating mechanism, with T{sub rh}>10{sup 11} GeV. Chaotic inflation with a quadratic potential is still compatible with the axion scenario, provided that the PecceiQuinn scale f{sub a} is close to 10{sup 10} or 10{sup 11} GeV. Isocurvature bounds eliminate the possibility of a larger f{sub a} and a small misalignment angle. We find that isocurvature constraints on the axion scenario must be taken into account whenever the scale of inflation is above 10{sup 12} GeV; below this scale, axionic isocurvature modes are too small to be probed by current observations.
 Authors:
 Departamento de Fisica Teorica CXI, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)
 Laboratoire d'Annecylevieux de Physique Theorique, BP110, F74941 AnnecyleVieux Cedex (France)
 Publication Date:
 OSTI Identifier:
 20933290
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 10; Other Information: DOI: 10.1103/PhysRevD.75.103507; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AMPLITUDES; AXIONS; CHAOS THEORY; EEV RANGE; INFLATIONARY UNIVERSE; MASS; NONLUMINOUS MATTER; PERTURBATION THEORY; POTENTIALS
Citation Formats
Beltran, Maria, GarciaBellido, Juan, and Lesgourgues, Julien. Isocurvature bounds on axions revisited. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVD.75.103507.
Beltran, Maria, GarciaBellido, Juan, & Lesgourgues, Julien. Isocurvature bounds on axions revisited. United States. doi:10.1103/PHYSREVD.75.103507.
Beltran, Maria, GarciaBellido, Juan, and Lesgourgues, Julien. Tue .
"Isocurvature bounds on axions revisited". United States.
doi:10.1103/PHYSREVD.75.103507.
@article{osti_20933290,
title = {Isocurvature bounds on axions revisited},
author = {Beltran, Maria and GarciaBellido, Juan and Lesgourgues, Julien},
abstractNote = {The axion is one of the best motivated candidates for particle dark matter. We study and update the constraints imposed by the recent CMB and LSS experiments on the mass of axions produced by the misalignment mechanism, as a function of both the inflationary scale and the reheating temperature. Under some particular although not unconventional assumptions, the axion induces isocurvature perturbations with an amplitude too large to be compatible with observations. Specifically, for inflation taking place at intermediate energy scales, we derive some restrictive limits which can only be evaded by assuming an efficient reheating mechanism, with T{sub rh}>10{sup 11} GeV. Chaotic inflation with a quadratic potential is still compatible with the axion scenario, provided that the PecceiQuinn scale f{sub a} is close to 10{sup 10} or 10{sup 11} GeV. Isocurvature bounds eliminate the possibility of a larger f{sub a} and a small misalignment angle. We find that isocurvature constraints on the axion scenario must be taken into account whenever the scale of inflation is above 10{sup 12} GeV; below this scale, axionic isocurvature modes are too small to be probed by current observations.},
doi = {10.1103/PHYSREVD.75.103507},
journal = {Physical Review. D, Particles Fields},
number = 10,
volume = 75,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}

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