Conveners
P5 - COSMOLOGY
- Nuno Miguel Santos (IST)
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Prof. Marco Peloso (University of Minnesota)31/05/2011, 16:30Many 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...Go to contribution page
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Dr Hyun Min Lee (CERN)31/05/2011, 16:45We consider the inflation model with non-minimal couplings where a singlet inflaton mixes with the Standard Model Higgs boson. The conditions required for the mixed inflation to happen constrain the Higgs and singlet couplings at unitarity scale, giving rise to additional constraints on the parameter space at low energy. We consider the LEP and electroweak precision data constraints on the...Go to contribution page
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Philip Stephens31/05/2011, 17:00The destabilising effect of supergravity corrections on traditional inflaton potentials is well known. Here I will offer a possible solution based on the presense of an inflection point in the flat direction potential for some Kahler interaction terms. We show that for reasonable choices of the Kahler potential it is possible for a vacuum energy density with no dynamics of its own, to...Go to contribution page
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Jacques Wagstaff31/05/2011, 17:15A Compelling Vector Curvaton Model and its Distinct Observational SignaturesGo to contribution page
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Dr Sergey Sibiryakov (INR RAS)31/05/2011, 17:30We 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...Go to contribution page
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Dr Grigoris Panotopoulos (University of Valencia)31/05/2011, 17:45We 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...Go to contribution page
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Mr Davide Cadamuro (Max-Planck-Institut für Physik)31/05/2011, 18:00Cosmological 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.Go to contribution page
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Dr Subhayan Mandal (University Of Liege)31/05/2011, 18:15We 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...Go to contribution page
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Mr Jose Miguel No (IPhT CEA Saclay)31/05/2011, 18:30It 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...Go to contribution page