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Speakers: José Juán Blanco Pillado (UPV-EHU Bilbao) and Krzysztof Turzynski (U. Warsaw). Location: Leiden.

Event details of Theoretical cosmology meeting
Date 6 April 2018
Time 14:00 -17:00


14:00 - 15:00 José Juán Blanco Pillado (UPV-EHU Bilbao)

Gravitational Waves from Cosmic Strings

15:00-15:30 Coffee

15:30-16:30 Krzysztof Turzynski (U. Warsaw)

Geometrical destabilization and reheating

16:30 Drinks


José Juán Blanco Pillado (UPV-EHU Bilbao)

Gravitational Waves from Cosmic Strings 

Abstract:  I will give a brief introduction to the theory of cosmic strings in the early universe and discuss recent progress in our understanding of the evolution of a string network.
I will then discuss the production of gravitational waves from this network and how this leads to prediction of a stochastic background of gravitational waves covering
a wide range of frequencies. Finally, I will also discuss the implications of these predictions for the gravitational  wave observations at the PTA range as well as the LIGO and LISA observatories.

Krzysztof Turzynski (U. Warsaw)

Geometrical destabilization and reheating

Abstract: In multi-field inflationary models, the curvature of the field space manifold can dominate the stabilizing force from the potential and destabilize inflationary trajectories: a phenomenon called geometrical destablization. An interesting example of this effect can be found in alpha-attractor T-models of inflation with small alpha <~10^(-3). The “spectator” field, which is heavy during inflation and does not participate in inflationary dynamics, becomes tachyonic as the inflaton gains speed and the perturbations of that dominate the dynamics of the early stages of reheating. As a result, the transition from the inflationary era to radiation domination era is practically instantaneous and much faster than previously found in an effective theory including only the inflaton field.


Snellius building (Niels Bohrweg 1, just facing the Oort building) , in room 408.