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Title: Particle abundances in our Universe: Deterministic, or randomly determined via quantum cosmology or inflationary quantum fluctuations

Abstract

There is a rather large class of particle species that may never achieve a thermal abundance after inflation. The abundance, relative to photons, of these particles (if stable), or the stable decay products from these particles, or the abundances of thermal relics diluted by an entropy-producing decay of such a particle, may not be possible to uniquely predict, even with full knowledge of the fundamental physics. Quantum cosmology, or inflationary quantum fluctuations, enables random processes to manifest themselves on very large scales, well beyond our horizon. Particle abundances that are not completely fixed by thermodynamics may be linked to these random processes, and significant large-scale variations in particle abundances may be realized without the exceedingly tiny probabilities that are associated with purely thermal processes. It is known that certain axion models may not yield a unique prediction for the axion abundance. After reviewing and further analyzing the axion case, we explore other models of particle species in which the element of chance may play a nontrivial role in determining the relic abundance. It appears that any relic abundance can be significantly affected by random processes, depending upon the details of the particle physics. Specific examples studied in this paper includemore » baryons, monopoles, other possible supermassive relics, gravitons, scalar field relics, and shadow matter. Also examined is the entropy-producing decay of a nonthermal relic, which may adjust the densities of all other frozen-out relics (e.g., supersymmetric relics), relative to the photon abundance, by a random amount. Simple models are provided in which the probability distributions of relic abundances relative to photons are explicitly calculated, and the possibility of obtaining a wide variety of abundances with modest changes in the probability is demonstrated.« less

Authors:
 [1]
  1. (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138 (United States))
Publication Date:
OSTI Identifier:
7049108
Alternate Identifier(s):
OSTI ID: 7049108
Resource Type:
Journal Article
Journal Name:
Physical Review, D (Particles Fields); (United States)
Additional Journal Information:
Journal Volume: 45:4; Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; RELICT RADIATION; ABUNDANCE; UNIVERSE; AXIONS; BARYONS; COSMOLOGY; ENERGY DENSITY; ENTROPY; GRAVITONS; MONOPOLES; NONLUMINOUS MATTER; PARTICLE DECAY; PHOTONS; PROBABILITY; QUANTUM MECHANICS; SCALAR FIELDS; THERMAL RADIATION; BOSONS; DECAY; ELECTROMAGNETIC RADIATION; ELEMENTARY PARTICLES; FERMIONS; GOLDSTONE BOSONS; GRAVITATIONAL RADIATION; HADRONS; MASSLESS PARTICLES; MATTER; MECHANICS; MICROWAVE RADIATION; PHYSICAL PROPERTIES; POSTULATED PARTICLES; RADIATIONS; THERMODYNAMIC PROPERTIES 662110* -- General Theory of Particles & Fields-- Theory of Fields & Strings-- (1992-)

Citation Formats

Hodges, H.M. Particle abundances in our Universe: Deterministic, or randomly determined via quantum cosmology or inflationary quantum fluctuations. United States: N. p., 1992. Web. doi:10.1103/PhysRevD.45.1113.
Hodges, H.M. Particle abundances in our Universe: Deterministic, or randomly determined via quantum cosmology or inflationary quantum fluctuations. United States. doi:10.1103/PhysRevD.45.1113.
Hodges, H.M. Sat . "Particle abundances in our Universe: Deterministic, or randomly determined via quantum cosmology or inflationary quantum fluctuations". United States. doi:10.1103/PhysRevD.45.1113.
@article{osti_7049108,
title = {Particle abundances in our Universe: Deterministic, or randomly determined via quantum cosmology or inflationary quantum fluctuations},
author = {Hodges, H.M.},
abstractNote = {There is a rather large class of particle species that may never achieve a thermal abundance after inflation. The abundance, relative to photons, of these particles (if stable), or the stable decay products from these particles, or the abundances of thermal relics diluted by an entropy-producing decay of such a particle, may not be possible to uniquely predict, even with full knowledge of the fundamental physics. Quantum cosmology, or inflationary quantum fluctuations, enables random processes to manifest themselves on very large scales, well beyond our horizon. Particle abundances that are not completely fixed by thermodynamics may be linked to these random processes, and significant large-scale variations in particle abundances may be realized without the exceedingly tiny probabilities that are associated with purely thermal processes. It is known that certain axion models may not yield a unique prediction for the axion abundance. After reviewing and further analyzing the axion case, we explore other models of particle species in which the element of chance may play a nontrivial role in determining the relic abundance. It appears that any relic abundance can be significantly affected by random processes, depending upon the details of the particle physics. Specific examples studied in this paper include baryons, monopoles, other possible supermassive relics, gravitons, scalar field relics, and shadow matter. Also examined is the entropy-producing decay of a nonthermal relic, which may adjust the densities of all other frozen-out relics (e.g., supersymmetric relics), relative to the photon abundance, by a random amount. Simple models are provided in which the probability distributions of relic abundances relative to photons are explicitly calculated, and the possibility of obtaining a wide variety of abundances with modest changes in the probability is demonstrated.},
doi = {10.1103/PhysRevD.45.1113},
journal = {Physical Review, D (Particles Fields); (United States)},
issn = {0556-2821},
number = ,
volume = 45:4,
place = {United States},
year = {1992},
month = {2}
}