Séminaire / Seminar GReCO |
| « The shapeshifting Universe - anisotropic cosmologies from gravitational tunneling and their observational signatures » |
|
J. Adamek |
| Higher dimensional gravity theories such as string theory may give rise to a vast multitude of different vacuum configurations with varying numbers of microscopic dimensions. It is possible that gravitational tunneling induces transitions between these configurations, very similar to first-order phase transitions in conventional false vacuum decay. If some microscopic dimensions decompactify in such a process, this may be perceived as an anisotropic cosmology from within the ""bubble universe."" These ideas lead to interesting phenomenological questions which establish the connection to cosmological observations. In particular, I will focus on the CMB as a decent probe for the signatures of anisotropic cosmology and discuss the constraints placed by observations on the parameters which characterize the anisotropy. Furthermore, anisotropic cosmology may be related to some of the anomalies already found in present experiments such as WMAP. |
|
lundi 22 novembre 2010 - 11:00 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |