Jean-Luc Lehners is ERC Starting Grant Holder at Max Planck Institute for Gravitational Physics in Potsdam and Postdoctoral Fellow at Princeton Center for Theoretical Science, Princeton University. His research interest is in cosmology, and in particular in how string theory (and supergravity) can provide new concepts to describe the era around the big bang. Recently, he has been working on ekpyrotic and cyclic models, in which the big bang results from the collision of two branes. In these models, the standard cosmological puzzles are resolved by a contracting phase preceding the big bang. This phase also provides a mechanism for generating cosmological perturbations, but interestingly with a significant non-Gaussian component. This departure from Gaussianity distinguishes ekpyrotic models from simple inflationary models and will be measured with high precision in upcoming satellite experiments and large scale structure surveys.