Astronomy & Astrophysics Seminar: Theoretical modeling of 21-cm signal and machine learning applications in 21-cm cosmology

Zoom: https://tau-ac-il.zoom.us/j/87185167411?pwd=FpTUyIgXaOturzOFSetA6pPVYQilen.1

Abstract:

The 21-cm signal from neutral hydrogen offers a powerful window into the high-redshift Universe, tracing the thermal and ionization history during Cosmic Dawn and the Epoch of Reionization. In this talk, I will present recent work on modeling the line-of-sight contribution of an excess radio background sourced by high-redshift galaxies. By incorporating this excess into semi-numerical simulations, we explore its impact on the global 21-cm signal and the power spectrum. This model constrains the clustering of high-redshift radio sources based on the existing upper limits from radio observations. Additionally, I will discuss how 21-cm observations can probe alternative dark matter scenarios, such as warm dark matter (WDM), by analyzing their distinctive imprints on the signal. In the second part of the talk, I will highlight the role of machine learning in advancing 21-cm cosmology, showing applications such as emulating the 21-cm power spectrum and classifying excess radio models. These tools offer promising pathways to efficiently extract astrophysical information from upcoming experiments like the Square Kilometre Array (SKA). 

Seminar Organizer: Dr. Jonathan Stern