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.
Utrecht Spring 2016
01/04/2016 @ 14:00 - 18:00
The April THC meeting will take place in Utrecht on April 1, 2016 (for real, no joke). We will have two speakers. Note that the ITF recently relocated from Minnaertgebouw to Buys Ballot Gebouw (big grey build just next to Minnaert, 7th floor).
14h00 – 15h00: Fabian Schmidt (MPA Garching, Germany)
From GUT scale to galaxies: probing the early universe with
large-scale structure
The statistics of galaxies and their shapes offer fascinating
possibilities for probing the early universe and physics of inflation.
Realizing this goal however requires a relativistic description of the
connection between the initial conditions from inflation and the
observed galaxies today, which is complicated both by galaxy formation
and the difficulties of relativistic perturbation theory. Significant
progress has been made recently in rigorous perturbative approaches
(capturing the physics of galaxy formation in a finite set of bias
parameters), and in disentangling physical effects from “gauge
artifacts” (for example, regarding f_NL in single-field inflation). I
will review the current state of theoretical understanding and describe
what insights nonlinear large-scale structure can offer into the physics
of inflation, both in terms of scalar modes and gravitational waves.
16h00 – 17h00: Daan Meerburg (CITA, Canada)
I will discuss to what degree the cosmic microwave background (CMB) can be used to constrain primordial non-Gaussianity involving one tensor and two scalar fluctuations, focusing on the correlation of one $B$-mode polarization fluctuation with two temperature fluctuations (BTT). In the simplest models of inflation, the tensor-scalar-scalar primordial bispectrum is non-vanishing and is of the same order in slow-roll parameters as the scalar-scalar-scalar bispectrum. I will show that constraints from an experiment like CMB-Stage IV using this observable are more than an order of magnitude better than those on the same primordial coupling obtained from temperature measurements alone. I will argue that $B$-mode non-Gaussianity opens up an as-yet-unexplored window into the early Universe, demonstrating that significant information on primordial physics remains to be harvested from CMB anisotropies. Specifically, if we measure any appreciable level of BTT correlation in the sky, its source is most likely not from inflation and as such can be used to directly test the inflationary paradigm.
17h00 – 18h00: Borrel