Here below are listed the upcoming IFPU colloquia, usually taking place once a month on Fridays at 11am. Past colloquia from the current program can be found in the recent colloquia page, while older events can be found in the 2020-2021 and 2019-2021 pages.

Andrei Mesinger (Scuola Normale Superiore, Pisa)
Forward modeling the first billion years
Friday, May 26th, 2023, 11am – Aula D (old SISSA building) & streaming

Abstract The birth of the first stars, black holes and galaxies heralded the end of the cosmic Dark Ages and the beginning of the Cosmic Dawn.  The light from these objects heated and ionized almost every atom in existence, culminating in the Epoch of Reionization: the final major phase change of the Universe.  This final frontier of astrophysical cosmology is undergoing a transition from an observationally-starved epoch to a “Big Data” field.  This process is set to culminate with upcoming Square Kilometre Array interferometric observations of the redshifted 21-cm line: providing a 3D map of the first billion years of our Universe.  With the SKA, we will be able to actually study the UV and X-ray properties of the first galaxies, as well as physical cosmology, which are encoded in the large-scale structure of the 21-cm signal. I will review the current status of observations of the EoR and Cosmic Dawn, before discussing the main challenges in modeling the 21-cm signal: a huge range of relevant scales and a large parameter space of astrophysical uncertainties.  I will review how simulations have adapted to address these challenges.  I show how the unprecedented size of the upcoming SKA dataset will allow us to recover properties of the (unseen!) first galaxies, in addition  to providing clean probes of cosmology through accoustic oscilations.  Finally I will demonstrate how simulation-based inference will be a powerful tool to study these upcoming (non-Gaussian) datasets.

Contact: Matteo Viel
Andrei Mesinger’s webpage