Conveners
P5 - COSMOLOGY
- Nuno Miguel Santos (IST)
Prof.
Marco Peloso
(University of Minnesota)
31/05/2011, 16:30
Many controlled realizations of inflation employ pseudo-scalar axions.
Pseudo-scalars φ are naturally coupled to gauge fields through c φ F F~. In the presence of this coupling, gauge field quanta are copiously produced by the rolling inflaton. The produced gauge quanta, in turn, source inflaton fluctuations via inverse decay. These cosmological perturbations add incoherently with the...
Jacques Wagstaff
31/05/2011, 17:15
A Compelling Vector Curvaton Model and its Distinct Observational Signatures
Dr
Sergey Sibiryakov
(INR RAS)
31/05/2011, 17:30
We present a model of dark energy where the parameter setting the rate of cosmic
acceleration has technically natural value, i.e. it does not receive corrections from other scales in the theory. The proposed acceleration mechanism appears generically in the low-energy limit of gravity with violation of Lorentz invariance and spontaneously broken internal global symmetries. The model is a...
Dr
Grigoris Panotopoulos
(University of Valencia)
31/05/2011, 17:45
We study a coupled quintessence model in which the interaction with the dark matter sector is a function of the quintessence potential. Such a coupling can arise from a field dependent mass term for the dark matter field. The dynamical analysis of a standard quintessence potential coupled with the interaction explored here shows that the system possesses a late time accelerated attractor. In...
Mr
Davide Cadamuro
(Max-Planck-Institut für Physik)
31/05/2011, 18:00
Cosmological precision data can be used to set very strict constraints on Axions and Axion-like particles produced thermally in the big bang. We briefly review the known bounds and propose two new constraints for Axions and ALPs decaying in the early universe, based upon the concomitant dilution of baryon and neutrino densities, using WMAP7 and other cosmological data.
Dr
Subhayan Mandal
(University Of Liege)
31/05/2011, 18:15
We establish the equation of motion of pseudoscalar particles coupled to an electromagnetic field in a classical gravitational background through the use of conformal time and flat geometry. We show that in general the expansion of the universe leads to larger mixing than in a stationary universe. We also show that for a broad range of parameters, one can obtain a resonance mixing, i.e. a...
Mr
Jose Miguel No
(IPhT CEA Saclay)
31/05/2011, 18:30
It is widely assumed that for the Electroweak Baryogenesis mechanism to be effective in generating the baryon asymmetry of the Universe, the first order phase transition bubbles have to expand at a subsonic speed (in order to allow for the diffusion of CP asymmetric currents in front of the wall). Here we present a new mechanism for Electroweak Baryogenesis that is effective for supersonic...
