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.
Amsterdam Fall 2015
04/12/2015 @ 12:30 - 17:30
Note: the UvA THC meeting will take place at NIKHEF instead, due to the unavailability of a suitable seminar room on Friday December 4. In addition there are in fact 3 (excellent!) speakers, which unfortunately implies we have to skip the sound-bite sessions this time around. See you all in room H331 at NIKHEF on Friday December 4.
12:30-13:30 in H331 (NIKHEF):
Speaker: Jens Chluba (IoA, Cambridge).
Title: Science with CMB Spectral Distortions: a New Window to Early-Universe and Particle Physics
Since COBE/FIRAS we know that the CMB spectrum is extremely close to a perfect blackbody. There are, however, a number of processes in the early Universe that should create spectral distortions at a level that is within reach of present day technology. I will give an overview of recent theoretical and experimental developments, explaining why future measurements of the CMB spectrum will open up an unexplored window to early-universe and particle physics, with possible non-standard surprises but also several guaranteed signals awaiting us. I will also highlight the complementarity of the distortion signals and the CMB anisotropies, illustrating how future distortions measurements will shed new light on different inflation models.
14:15-15:15 in H331 (NIKHEF):
Speaker: David Marsh (King’s College London)
Title: Axion Cosmology, from strings to dwarf galaxies
Axions comprise a broad class of particles that can play a major role in explaining the unknown aspects of cosmology. They are also extraordinarily well-motivated within high energy physics, and so axion cosmology offers us a unique view onto these theories. I will provide an overview of theories of axions in field theory, and their role in solving the strong-CP problem. I will then motivate the existence of the “String Axiverse:” the idea that a plethora of axions are a generic prediction of low energy string theory. I then discuss axion cosmology, and how the CMB and large scale structure can be used to place robust bounds on axion (and other boson) masses as dark matter candidates. Next, I will show how the so-called “small-scale crises” of cold dark matter can be solved by a generic string axion, pointing to a specific axion mass and decay constant scale. This scenario makes predictions about future measurements of the epoch of reionization and high-z galaxy formation. Along the way, and given time, I will discuss the status and progress of axion direct detection experiments. In particular, CASPEr-Wind may be able to detect the axion responsible for solving the small-scale crises.
16:00-17:00 in H331 (NIKHEF):
Speaker: Raphael Flauger (University of Texas, Austin)
Title: On Tensions, Systematics and B-modes