# Cosmic bounces and cyclic universes

@article{Lehners2011CosmicBA, title={Cosmic bounces and cyclic universes}, author={Jean-Luc Lehners}, journal={Classical and Quantum Gravity}, year={2011}, volume={28}, pages={204004} }

Cosmological models involving a bounce from a contracting to an expanding universe can address the standard cosmological puzzles and generate 'primordial' density perturbations without the need for inflation. Some such models, in particular the ekpyrotic and cyclic models that we focus on, fit rather naturally into string theory. We discuss a number of topics related to these models: the reasoning that leads to the ekpyrotic phase, the predictions for upcoming observations, the differences…

## 58 Citations

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