Bang or Bounce

TL;DR

This paper explores a cyclic cosmology model using the Come Back Empty assumption with a cosmological constant, leading to an infiniverse that naturally explains flatness and homogeneity without requiring inflation.

Contribution

It demonstrates that the CBE strategy can be applied with a cosmological constant, producing a multiverse and addressing the TEC without inflation.

Findings

CBE contraction naturally leads to flatness and homogeneity.

The model suggests an infiniverse with implications for predictability.

No inflationary era is necessary at the start of expansion.

Abstract

Following up an earlier suggestion of how the Tolman Entropy Conundrum (TEC) can be solved in a cyclic cosmology using the Come Back Empty (CBE) assumption with phantom dark energy, here we show how the same CBE strategy may work with a cosmological constant in the expansion era. As in the earlier case, this leads to a multiverse, actually an infiniverse, with the concomitant issues of predictivity and testability. Here we show how extreme flatness and homogeneity at the bounce are natural properties of the contraction era, interestingly without any necessity for an inflationary era at the beginning of the present expansion. Essential ingredients in the solution of TEC are CBE contraction and a careful treatment of what is meant by the visible universe.