Theoretical Cosmology meetings
To actively encourage the field of theoretical cosmology and to set an informal stage for the exchange of ideas, the Dutch theoretical cosmology community organizes Friday afternoon meetings approximately 6 times a year — usually on the first Friday of the month. The meetings typically start in the afternoon with a main speaker, followed by a short break to continue with another seminar or journal club discussion on some topic of current interest. We end the afternoon with drinks. The supporting institutes in Leiden, Amsterdam, Groningen, Utrecht where recently joined by the strings and cosmology group in Leuven and take turns in hosting the event.
- This event has passed.
Groningen Spring 2018
08/06/2018 @ 13:00 - 17:00
Groningen, June 8th, 2018
Location: lecture room 112 in the Oude Boteringstraat 34 (Faculty of Arts), Groningen
13:00 – 14:00: Talk by Djuna Croon (Dartmouth College),
Title: 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.
14:30 – 15:30: Talk by Tomi Koivisto (Nordita)
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.
16:00 – 17:30: Talk by Anupam Mazumdar (Groningen)
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.