Abstract
Based on concepts drawn from the ekpyrotic scenario and M-theory, we
elaborate our recent proposal of a cyclic model of the Universe. In this model,
the Universe undergoes an endless sequence of cosmic epochs which begin with
the Universe expanding from a `big bang' and end with the Universe contracting
to a `big crunch.'
Matching from `big crunch' to `big bang' is performed according to the
prescription recently proposed with Khoury, Ovrut and Seiberg. The expansion
part of the cycle includes a period of radiation and matter domination followed
by an extended period of cosmic acceleration at low energies. The cosmic
acceleration is crucial in establishing the flat and vacuous initial conditions
required for ekpyrosis and for removing the entropy, black holes, and other
debris produced in the preceding cycle. By restoring the Universe to the same
vacuum state before each big crunch, the acceleration insures that the cycle
can repeat and that the cyclic solution is an attractor.
Users
Please
log in to take part in the discussion (add own reviews or comments).