Nordita Astrophysics Seminars

Resolving cosmological tensions with Type Ia supernovae

by Suhail Dhawan (Institute of Astronomy and Kavli Institute for Cosmology, University of Cambridge)

Europe/Stockholm
Albano 3: 6228 - Mega (22 seats) (Albano Building 3)

Albano 3: 6228 - Mega (22 seats)

Albano Building 3

22
Description
The Hubble tension is arguably the biggest open question in modern cosmology. While it is the most significant signature of new cosmological physics, it is imperative to test whether unknown systematics are at play. In my talk, I will summarise our recent work on developing the distance ladder with novel probes like the tip of the red giant branch to use Type Ia supernovae (SNe Ia) from the Zwicky Transient Facility for measuring the Hubble constant.
Strong gravitational lensing is an independent channel with which SNe Ia weigh in on the tension. Since lensed SNe measure time delay distances this probe has complete independent systematics to the local distance ladder and hence, is a powerful way to measure H0. I will talk about our recent work with wide-field surveys to discover and characterise lensed SNe. An interlinked problem in cosmology today is the test for whether the universe is isotropic. Our recent work shows some indications for potential deviations from isotropy and forecasts suggest the exciting possibility to strongly confirm or refute this claim.