The 4th UniverseNet School - Frontiers of Particle Cosmology

Session

6 talks (Chair: Konstantinos DIMOPOULOS)

17 Sept 2010, 16:30

Lecce, Università del Salento

48. Ms. DEMOZZI, Vittoria (LMU Munich): Non-Gaussianity in the curvaton landscape

17/09/2010, 16:30

We consider the curvaton scenario applied not only to the observable patch of the Universe, but to the entire Universe. On the scales of the entire Universe the homogeneous component of the curvaton field $\sigma_{0}$ is a random value with a probability distribution that we can compute. The entire Universe is pictured as a ``curvaton landscape''. We show that the non-linearity parameter...

61. Mr. FONSECA, José (ICG Portsmouth): Large-scale Perturbations from the Waterfall Field in Hybrid Inflation

17/09/2010, 16:45

We estimate large-scale curvature perturbations from isocurvature fluctuations in the waterfall field during hybrid inflation, in addition to the usual inflaton field perturbations. The tachyonic instability at the end of inflation leads to an explosive growth of super-Hubble scale perturbations, but they retain the steep blue spectrum characteristic of vacuum fluctuations in a massive field...

63. Dr. MULRYNE, David (Imperial College London): Moment transport equations for Non-Gaussianity in models with many fields

17/09/2010, 17:00

I will discuss inflationary models with large numbers of active fields, and numerical methods for calculating the non-Gaussianity produced in such models. In particular, I will discuss the method of `moment transport' which directly evolves the moments of the probability distribution for the curvature perturbation on super-horizon scales.

32. Dr. PANOTOPOULOS, Grigoris (University of Valencia): Constraints on quintessence coupled models through energy dependent coupling

17/09/2010, 17:15

We study coupled quintessence models in which the interaction with dark matter is driven by some power of the quintessence potential. We show that those models can emerge from a Lagrangian formulation, and can lead to a accelerating stable fixed point. We also provide the bounds on the parameters of the models using supernovae, CMB, BAO and $H_0$ data.

34. Dr. TAVAKOLI, Farhad (Islamic Azad University, Tehran): The effect of self-force on a freely falling massive charged particle in de-Sitter universe

17/09/2010, 17:30

Observations coming from the astrophysical data indicate that we live in a expanding universe where its evolution is dominated by a small positive cosmological constant. Mathematically this model can be explained by the de Sitter space-time. In this work we study a freely falling massive charged particle in de Sitter space-time. However due to the effect of the charge and mass the particle...

64. Mr. WELLER, Joel (University of Sheffield): Coupled DBI Cosmology

17/09/2010, 17:45

The availability of high precision observational data in cosmology means that it is possible to go beyond the simple descriptions of cosmic inflation in which the expansion is driven by a single slowly rolling scalar field. One set of models of particular interest involve the Dirac-Born-Infeld (DBI) action, arising in string cosmology, in which the dynamics of the inflaton field are affected...