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 2015
06/11/2015 @ 12:30 - 18:00
From 12.30-14h in HL106 (Huygens Lab building):
Lunch (10 minute) ‘sound-bite’ session
- Remko Klein (RUG) – An introduction to Galileons and higher order derivatives in scalar field theories
- Anja Marunovic (UU) – Topological inflation and graceful exit [based on http://arxiv.org/abs/1508.05010 and possible extensions of it]
- Antonella Garzilli (UL) – Features in the Lyman α forest spectrum [http://arxiv.org/abs/1510.07006]
From 14-15h in HL106 (Huygens Lab building):
Speaker: Giulio Fabbian (SISSA).
Title: Modeling and measuring CMB lensing in the cross-correlation era.
Being less sensitive to systematic effects, the cross-correlations between Cosmic Microwave Background (CMB) data sets and large-scale structures surveys are expected to provide excellent astrophysical and cosmological constraints in the upcoming years. The ongoing CMB polarization experiment POLARBEAR and its upgrade, the Simons Array, will provide one of the best CMB data set for cross-correlation studies. In this talk I will review the latests results and data analysis activity of POLARBEAR and discuss the capabilities of the Simons array for cross-correlation science. If time allows, I will also present recent numerical results aiming at a joint and realistic modeling of the observables involved in cross-correlation studies, the CMB lensing and large-scale structure distribution.
From 15:30-16:30h in HL106 (Huygens Lab building):
Speaker: Jorge Noreña (University of Geneva)
Title: The squeezed limit of observable correlation functions
If the evolution of the universe is nearly adiabatic at large scales, a long-wavelength mode of the gravitational potential has no physical effect on short-scale physics. This means that a mode whose characteristic size is larger than all the scales accessible to a specific experiment is unobservable. I will first show this explicitly in the language of Weinberg\u2019s adiabatic modes. This fact greatly simplifies the computation of observable quantities in the presence of a long-wavelength mode, which can be used to compute the squeezed limit of 3-point correlation functions. The measurement of this limit contains information about the number and nature of the degrees of freedom active during the earliest stages of the evolution of the universe. I will show how this arguments can be applied to the 3-point function of the CMB temperature and the galaxy number over-density. I will briefly discuss the prospects of observing the galaxy number over-density 3-point function in this limit and the challenges that can arise.