 Jean-Luc Lehners
2007-2010 Postdoctoral Fellow
Cosmology & String Theory
609-258-5596
410 Jadwin Hall
E-mail
My 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, I have 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.
Recent publications:
- Multifield Cosmological Perturbations at Third Order and the Ekpyrotic Trispectrum
J-L. Lehners and S. Renaux-Petel, arXiv:0906.0530 [hep-th].
- Dark Energy and the Return of the Phoenix Universe
J-L. Lehners and P.J. Steinhardt, Phys. Rev. D79, 063503 (2009).
- Ekpyrotic and Cyclic Cosmology
J-L. Lehners, Phys. Rept. 465, 223 (2008).
- Intuitive Understanding of Non-Gaussianity in Ekpyrotic and Cyclic
Models
J-L. Lehners and P.J. Steinhardt, Phys. Rev. D78, 023506 (2008).
- Non-Gaussian Density Fluctuations from Entropically Generated Curvature
Perturbations in Ekpyrotic Models
J-L. Lehners and P.J. Steinhardt, Phys. Rev. D77, 063533 (2008).
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