Theoretical cosmology meeting

08June2018 13:00 - 17:30

Event

Speakers: Djuna Croon (Dartmouth College), Tomi Koivisto (Nordita), and Anupam Mazumdar (Groningen). Location: Groningen.

Programme

Location: lecture room 112, Faculty of Arts, Oude Boteringstraat 34, Groningen >>GoogleMaps.

13:00 – 14:00 Djuna Croon (Dartmouth College) - Model discrimination in Gravitational Waves from Phase Transitions 

14:30 – 15:30 Tomi Koivisto (Nordita) - Nonlocal theories of gravity 

16:00 – 17:30 Anupam Mazumdar (Groningen) - Non-singular blackholes in Infinite derivative gravity

Abstracts 

Djuna Croon (Dartmouth College)

Model discrimination in Gravitational Waves from Phase Transitions 

Besides the EWPT, various dark phase transitions could give an observable broken power-law spectrum at LISA. In this talk I will consider the opportunities for model discrimination, by examining the thermal parameters predicted in classes of models. These thermal parameters are functions of the parameters in the scalar potential, the quantum numbers of the scalar, and the couplings to fermions. I will also comment on exotic spectra from multi-step phase transitions, and finish with an outlook to future work. 

Tomi Koivisto (Nordita)

Nonlocal theories of gravity 

Ghost-free non-local extensions of General Relativity theory are discussed,  both at the ultra-violet and in the infra-red. The most general metric theory is analysed in flat space and shown to contain theories which do not introduce new degrees of extra degrees of freedom but are non-singular in the ultra-violet, when allowing for nonlocal, infinite-order derivative operators. These theories are also presented in a new first order formulation which is simpler though more general. Also, nonlocal infrared modifications of gravity considered, reviewing some models that have been proposed models to address the problems of the cosmological constant and dark energy. 

Anupam Mazumdar (Groningen)  

Non-singular blackholes in Infinite derivative gravity 

I will give some new results in infinite derivative gravity to argue that how and why astrophysical blackholes can avoid singularity and the event horizon.

Location

Location: lecture room 112, Faculty of Arts, Oude Boteringstraat 34, Groningen >>GoogleMaps.

source: THC@NL

Published by  D-ITP