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Speakers: Zvonimir Vlah (CERN), Florent Mertens (RUGroningen), and Suvodip Mukherjee (GRAPPA). Location: Utrecht, room 7.12, Buys Ballotgebouw, Princetonplein 5.

Detail Summary
Date 10 January 2020
Time 13:00 -17:30
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Programme  

13:30 - 14:30 Zvonimir Vlah (CERN) - Cosmological structure formation and the shapes in the sky

14:30 - 15:00 Coffee Break

15:00 - 16:00 Florent Mertens (RUGroningen) - Observing the epoch of reionization and Cosmic Dawn with LOFAR and NenuFAR

16:00 - 17:00 Suvodip Mukherjee (GRAPPA) - A new window to Axion-Like Particles from the upcoming CMB experiments

17:00 - end Borrel

Abstracts

Zvonimir Vlah (CERN) 

Cosmological structure formation and the shapes in the sky

Abstract: Understanding dark matter inhomogeneities and the corresponding tracers, like galaxies, on large cosmological scales, is considered one of the pillars of the standard cosmological model. Detailed understanding of these inhomogeneities is crucial for the interpretation of observational data from numerous current and future surveys. I will present recent developments in the analytic approaches of describing the formation of nonlinear structure in the universe based on the recent statistical field theory methods. In the second part, I will present a formalism based on the effective field theory methods to describe the statistics of shapes on the sky, and its application to the intrinsic alignments of galaxies.

Florent Mertens (RUGroningen)

Observing the epoch of reionization and Cosmic Dawn with LOFAR and NenuFAR


Abstract: Low-frequency observations of the redshifted 21cm line promise to open a new window onto the first billion years of the cosmic history, allowing us to directly study the astrophysical processes occurring during the Epoch of Reionization (EoR) and the Cosmic Dawn (CD). This exciting goal is challenged by the difficulty of extracting the feeble 21-cm signal buried under astrophysical foregrounds orders of magnitude brighter and contaminated by numerous instrumental systematics. Several experiments such as LOFAR, MWA, HERA and NenuFAR are currently underway aiming at statistically detecting the 21-cm brightness temperature fluctuations from the EoR and CD. While no detection is yet in sight, considerable progress has been made recently. In this talk I will review the latest development of the LOFAR Epoch of Reionization and NenuFAR Cosmic Dawn key science projects.

Suvodip Mukherjee (GRAPPA)

A new window to Axion-Like Particles from the upcoming CMB experiments


Abstract: Cosmic Microwave Background (CMB) is a powerful probe to the Universe which carries signatures of cosmic secrets over a vast range of redshifts. Along with spatial fluctuations, spectral distortions of CMB blackbody are also a rich source of cosmological information. In my talk, I will introduce a new kind of spectral distortion of CMB which can arise due to the conversion of CMB photons into Axion-Like Particles (ALPs) in the presence of an external magnetic field. This effect leads to both polarized and unpolarized spatially varying spectral distortion signal with a unique spectral shape when CMB photons undergo resonant and non-resonant conversion into ALPs in the presence of the magnetic field of Milky Way, galaxy clusters and voids. I will discuss the spatial structure of this distortion which can arise from Milky Way and galaxy clusters and will show its uniqueness from other known cosmological and astrophysical signals. I will present the first all-sky map of the ALPs distortion which is obtained using the data of Planck satellite and will discuss the capability of this new cosmological window to probe ALPs from the upcoming ground-based and space-based CMB experiments.

Location

The meeting will take place in room 7.12, Buys Ballotgebouw, Princetonplein 5, Utrecht. 

About

These meetings occur (roughly) every month and are hosted by universities across the Netherlands and sometimes Belgium, gathering the local cosmology community. Some of these talks might be of interest also for string and the Amsterdam GRAPPA groups, so we encourage you to subscribe to the THC mailing list:

and to follow our website http://cosmology.nl/ to keep up to date on THC meetings dates and programs.