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.
Leiden Fall 2019
08/11/2019 @ 13:00 - 17:30
Leiden, November 8th.
The meeting will take place in Leiden, at the Institute Lorentz for Theoretical Physics, Niels Bohrweg 2, Leiden in room Oort 276.
13:00 – 14:00: Talk by David Harvey (Institute Lorentz)
Title:Testing dark matter self-interactions with future all-sky surveys
Abstract:
Probing the interactions of dark matter provides a pathway to understanding its nature, however in the absence of any detection, we are being forced to diversify our search and look beyond the usual coupling between dark matter and the Standard Model of Particle Physics.
In the currently accepted cosmological model, dark matter is assumed to be collisionless, yet the self-interaction cross-section actually remains relatively unconstrained, with viable models able to modify the structure of galaxies and clusters of galaxies on an observable scale. In this talk I will present the cosmological manifestations of a finite self-interaction cross-section, what are the main hurdles we face in constraining this and how the advent of all-sky telescopes such as LSST and Euclid will revolutionise our view of the dark sector.
14:00 – 14:30: Coffee Break
14:30 – 15:30: Talk by Miguel Zumalacarregui(UC Berkeley & IPhT Saclay)
Title: No LIGO MACHO: bounds on primordial black holes as dark matter from gravitational lensing of supernovae
Abstract:
Black hole mergers detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) have revived dark matter models based on primordial black holes (PBH) or other massive compact halo objects (MACHO). These objects would be abundant in the mass range 1-100 M_Sun, where rather remarkably, previous bounds were the weakest. I will present constraints on the PBH abundance and mass using the gravitational lensing magnification of type Ia supernovae using current data. Our results rule out the hypothesis of MACHO/PBH comprising the totality of the dark matter at high significance in the mass range M > 0.01 M_Sun. Eliminating the possibility of a LIGO-mass MACHO constraints early-universe models that produce PBHs and further strengthens the case for lighter dark matter candidates.
15:30 – 16:30: Talk by Alexander Westphal(DESY)
Title: Flattened Axion Monodromy Beyond Two Derivatives
Abstract:
16:30 – 17:30: Borrel