Thermodynamics and the end of a closed Universe

If the Universe is closed and began with low entropy, it began without an initial singularity in an unstable de Sitter phase. Because of the irreversible nature of the processes, when the closed Universe ultimately contracts it will not bounce, but will go into a 'final crunch'. In the final reheating, symmetry will be restored, but the contraction will never become deflationary. A closed Universe therefore lives only once, and can start with a whimper, but goes out with a bang. (author)