Conveners
06 - Early universe
- Daniel G. Figueroa (CERN)
06 - Early universe
- Daniel G. Figueroa (CERN)
Craig Hogan
(U. Chicago and Fermilab)
14/12/2015, 14:00
Talk
It is proposed that small amplitude, coherent rotational fluctuations arise from the emergence of nearly-classical non-rotating inertial frames from Planck scale quantum elements. An exact form is calculated for Planck scale correlations in the signal of a Sagnac type interferometer, where the light path encloses a large area of arbitrary shape, normalized using area quantization from...
Dr. Bikash Chandra PAUL
(University of North Bengal)
14/12/2015, 14:21
Talk
Emergent universe (EU) scenarios describe the evolution of a static Einstein universe in the infinite past whereby certain problems associated with the big-bang singularity can be circumvented. A flat universe composed of interacting fluids with a non-linear equation of state within the EU scenario leads to a viable cosmological model accommodating the presently observed accelerating era, as...
Dragan Hajdukovic
(Institute of Physics, Astrophysics and Cosmology)
14/12/2015, 14:42
Talk
It was recently suggested that what we call dark matter and dark energy, can be explained as the local and global effects of the gravitational polarization of the quantum vacuum by the immersed Standard Model matter. This result appears as the consequence of the working hypothesis that by their nature quantum vacuum fluctuations are virtual gravitational dipoles. Here, we argue that, as a...
Jonathan Braden
(University College London)
14/12/2015, 15:03
Talk
First-order phase transitions proceed through the nucleation and subsequent collision of bubbles. In false vacuum eternal inflation, such collision events are ubiquitous and provide a possible avenue to observationally test the multiverse. They also play an important role in early high temperature phase transitions.
I will present results for the full three-dimensional nonlinear dynamics...
Lavinia Heisenberg
(ETHZ - ETH Zurich)
14/12/2015, 15:24
Talk
In order to regularize the energy of point-like charged particles, Born and Infeld introduced a modification of the Maxwell lagrangian that naturally imposes an upper bound on electromagnetic fields. This approach was later taken by Deser and Gibbons to propose an analogous modification for gravity. I will review these ideas and discuss a scenario where inflation could be supported by a set of...
Andrey Shkerin
(EPFL)
14/12/2015, 16:15
Talk
We study Coleman – De Luccia tunneling of the Standard Model Higgs field during
inflation in the case when the electroweak vacuum is metastable. We verify that the
tunneling rate is exponentially suppressed. The main contribution to the suppression
is the same as in flat space-time. We analytically estimate the corrections due to the
expansion of the universe and an effective mass term in...
Dr
Daniel G. Figueroa
(CERN)
14/12/2015, 16:35
Talk
I will present the cosmological implications of the decay of the Standard Model Higgs after Inflation, when assuming a post-inflationary/pre-BBN expansion history driven by a stiff source with equation of state w > 1/3. In particular, I will discuss first the realisation of a successful 'reheating' mechanism, and secondly, the production of a large background of gravitational waves by the...
Francesco Cefalà
(University of Basel)
14/12/2015, 16:55
Talk
I will first give a short overview of preheating after hilltop inflation. In the main part of the talk I will discuss how the dynamics can change
when the inflaton couples to another scalar field, e.g. a right-handed sneutrino, which provides a mechanism for generating the correct initial conditions for inflation and also a decay channel for the inflaton that allows for non-thermal...
Stefano Orani
(Basel University)
14/12/2015, 17:15
Talk
During hilltop inflation, the inflaton rolls away from the maximum of its potential and towards the minimum where the universe reheats. The first stage of reheating, preheating, is non-perturbative and, in this model, localized oscillating bubbles of the inflaton field, called oscillons, are formed. Furthermore, when other fields are present, they can be produced via a parametric resonance...
Christian Byrnes
(University of Sussex (GB))
14/12/2015, 18:15
Talk
It is both remarkable, and disappointing, that only two parameters describing the primordial perturbations can explain the statistical properties of millions of CMB temperature perturbations. However, the persistence of several large-scale cosmological anomalies in WMAP and Planck satellite data may provide a clue to new physics. I will discuss how inflationary models can explain the observed...
