Files
Document type
ArticleVersion
Published versionPublication date
All rights reserved
Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/12407
Particle creation due to cosmological contraction of extra dimensions
Journal Title
Director/Tutor
Additional contribution
Journal ISSN
Volume Title
Abstract
Particle production in a cosmological spacetime with extra dimensions is discussed. A five-dimensional cosmological model with a three-dimensional space expanding isotropically like in a radiative Friedmann-Robertson-Walker model and an internal space contracting to a constant small size is considered. The parameters of the model are adjusted so that time variations in internal space are compatible with present limits on time variations of the fundamental constants. By requiring that the energy density of the particles produced be less than the critical density at the radiation era we set restrictions on two more parameters: namely, the initial time of application of the semiclassical approach and the relative sizes between the internal space and the horizon of the ordinary Universe at this time. Whereas the production of massless particles allows a large range of variation to these parameters, the production of massive particles sets severe constraints on them, since, if they are overproduced, their energy density might very soon dominate the Universe and make cosmological dimensional reduction by extradimensional contraction unlikely.
Related resource
Subject (English)
Citation
Citation
GARRIGA TORRES, Jaume and VERDAGUER OMS, Enric. Particle creation due to cosmological contraction of extra dimensions. Physical Review D. 1989. Vol. 39, num. 4, pags. 1072-1083. ISSN 0556-2821. [consulted: 16 of October of 2026]. Available at: https://hdl.handle.net/2445/12407