Cosmological Models with no Big Bang

Abstract

In the late 1990s, observations of Type Ia supernovae led to the astounding discovery that the universe is expanding at an accelerating rate. The explanation of this anomalous acceleration has been one of the great problems in physics since that discovery. In this talk, I will present cosmological models [1,2,3] that can explain the cosmic acceleration without invoking mysterious, unseen “dark energy” to account for the expansion. There are four distinguishing features of these models: 1) the speed of light and the gravitational “constant” are not constant, but vary with the evolution of the universe, 2) time has no beginning and no end; i.e., there is neither a big bang nor a big crunch singularity, 3) the spatial section of the universe is a 3-sphere, ruling out the possibility of a flat or hyperboloid geometry, and 4) the universe experiences phases of both acceleration and deceleration. One of these models is selected and tested against current cosmological observations of Type Ia supernovae, and is found to fit the redshift-luminosity distance data quite well. References 1. arXiv:1007.1750v1 2. http://www.technologyreview.com/blog/arxiv/26170/3.http://www.physorg.com/news199591806.html