Observational constraints on higher-dimensional and variable-[lambda] cosmologies
Date
2017-06-30
Authors
Overduin, J. M.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Nonstandard cosmological models of two broad classes are examined: those in which there are more than four spacetime dimensions, and those in which there is a variable cosmological “constant” Λ. We test claims that a number of higher-dimensional models give rise to inflation. New constraints are placed on such models, and a number of them are ruled out. We then investigate the potential of variable-Λ theories to address the problem of the initial singularity. We consider a number of different phenomenological representations for this parameter, assessing their implications for the evolution of the cosmological scale factor as well as a range of observational data. In several cases we find nonsingular models which are compatible with observation.
Description
Keywords
Astronomy, Cosmology, Constraints (Physics)