The first measurements of acoustic peaks in the CMB anisotropies have confirmed that the birth of fluctuations may have taken place during an early inflationary era of the universe. In this domain, our activities deal with the construction of explicit models of inflation as well as the extraction of their observable consequences. Our fields of expertise comprise some actively debated subjects as the trans-Planckian problem, inflation with non-minimally coupled scalar fields, DBI- and brane inflation as in the context of String Theory (KKLMMT models). For all these systems, we are maintaining various numerical tools to compute the relevant observables required for comparison with CMB data. Special attention is devoted to the class of multi-field inflationary models. The hybrid mechanism is expected to be realized within high energy particle physics models whereas Higgs inflation is a candidate of choice for TeV scale inflation.
External collaborators: Jérôme Martin (Institut d'Astrophysique de Paris, France), Sébastien Clesse (Cambridge University, U.K.).
Observations show that magnetic fields are present everywhere in the universe. Planets, galaxies, clusters carry magnetic fields of varying strength and coherence size. There are evidences of their presence also in the intergalactic medium and this strongly suggests that their origin might be primordial. A promising candidate for the generation of primordial magnetic fields is inflation. Our work concerns the construction of efficient inflationary mechanisms which could produce the large-scale magnetic fields observed today and it deals in particular with the possible effects that such mechanisms have on the physics of the universe after inflation.
External collaborators: Chiara Caprini (CEA Saclay, France).
