From what (little) I understand the classical interpretation of the red shift is really getting hammered.
Probably the most popular alternative is the cyclical universe where it contracts to a tiny ( but not infinity small volume ) only to re-expand.
RE: Probably the most popular alternative is the cyclical universe where it contracts to a tiny ( but not infinity small volume ) only to re-expand.
The The Steinhardt–Turok model has been proposed for a long time.
It is not without its problems.
Mathematical physicist and physical chemist (who worked with Einstein at Caltech), showed, the earlier cyclic model failed because the universe would undergo inevitable thermodynamic heat death.
I know that the newer cyclic model evades this by having a net expansion each cycle, preventing entropy from building up. However, there remain major open issues in the model. Foremost among them is that colliding branes are not understood by string theorists, and nobody knows if the scale invariant spectrum will be destroyed by the big crunch.
Moreover, as with cosmic inflation, while the general character of the forces (in the ekpyrotic scenario, a force between branes) required to create the vacuum fluctuations is known, there is no candidate from particle physics.