Cosmological effects of radion oscillations
Loading...
Date
Authors
Perivolaropoulos, L.
Sourdis, C.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Type
Type of the conference item
Journal type
peer reviewed
Educational material type
Conference Name
Journal name
Physical Review D
Book name
Book series
Book edition
Alternative title / Subtitle
Description
We show that the redshift of pressureless matter density due to the expansion of the universe generically induces small oscillations in the stabilized radius of extra dimensions (the radion field). The frequency of these oscillations is proportional to the mass of the radion and can have interesting cosmological consequences. For very low radion masses m(b)[m(b)similar to(10-100)H(0)similar or equal to10(-32) eV] these low frequency oscillations lead to oscillations in the expansion rate of the universe. The occurrence of acceleration periods could naturally lead to a resolution of the coincidence problem, without need of dark energy. Even though this scenario for low radion mass is consistent with several observational tests it has difficulty meeting fifth force constraints. If viewed as an effective Brans-Dicke theory it predicts omega=-1+1/D (D is the number of extra dimensions), while experiments on scales larger than 1 mm imply omega>2500. By deriving the generalized Newtonian potential corresponding to a massive toroidally compact radion we demonstrate that Newtonian gravity is modified only on scales smaller than m(b)(-1). Thus, these constraints do not apply for m(b)>10(-3) eV (high frequency oscillations) corresponding to scales less than the current experiments (0.3 mm). Even though these high frequency oscillations cannot resolve the coincidence problem they provide a natural mechanism for dark matter generation. This type of dark matter has many similarities with the axion.
Description
Keywords
high-frequency oscillations, extra dimensions, submillimeter dimensions, dark-matter, inflation, hierarchy, models, tev, compactification, stabilization
Subject classification
Citation
Link
<Go to ISI>://000179081500044
http://prd.aps.org/abstract/PRD/v66/i8/e084018
http://prd.aps.org/abstract/PRD/v66/i8/e084018
Language
en
Publishing department/division
Advisor name
Examining committee
General Description / Additional Comments
Institution and School/Department of submitter
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών και Τεχνολογιών. Τμήμα Βιολογικών Εφαρμογών και Τεχνολογιών