Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/12407
Title: Particle creation due to cosmological contraction of extra dimensions
Author: Garriga Torres, Jaume
Verdaguer Oms, Enric, 1950-
Keywords: Cosmologia
Teoria quàntica de camps
Partícules (Física nuclear)
Solucions numèriques
Cosmology
Quantum field theory
Particles (Nuclear physics)
Numerical solutions
Issue Date: 1989
Publisher: The American Physical Society
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.
Note: Reproducció digital del document publicat en format paper, proporcionada per PROLA i http://dx.doi.org/10.1103/PhysRevD.39.1072
It is part of: Physical Review D, 1989, vol. 39, núm. 4, p. 1072-1083
URI: http://hdl.handle.net/2445/12407
ISSN: 0556-2821
Appears in Collections:Articles publicats en revistes (Física de la Matèria Condensada)

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