Looking at our expanding Universe through Gravitational waves & 1,2,3 and 4

Speakers: Daniele Celoria & Nandita Khetan 
Affiliation: University of Queensland

Abstracts

Looking at our expanding Universe through Gravitational waves by Nandita Khetan

Since their first detection in 2015, Gravitation waves are sort of the ‘new kid in the block’ and a super cool one! They encode immense information about their source and the medium they travel through offering us this whole new window to look at the Universe. I will talk about how we can use them to measure the rate of expansion of our Universe, the Hubble constant (H0), a fundamental parameter describing the evolution history of our Universe, and one that is presently under ‘tension’ due to its discrepant values inferred from other methods.

Biography

Following her masters in Germany in particle detectors, Nandita completed her Phd in Italy in 2021 at Gran Sasso Science Institute, mainly focusing on supernova cosmology. She then moved to Denmark for her Postdoc where she explored some exotic transients along with a lot of cakes! She then moved to UQ in 2023 finally for some sunshine!

1,2,3 and 4 by Daniele Celoria 

We'll have a brief introduction on a few topics in low-dimensional topology. More specifically, we'll see some unexpected interactions between knots and 4-dimensional manifolds, and how the former are used to probe the existence of non-standard smooth structures on the latter. The main protagonist will be the concordance group, a mysterious algebraic object that "combines all dimensions" from 1 to 4.

Biography

Daniele did his undergrad studies in Pisa (with a thesis on knots & contact geometry), his PhD in Florence (with a thesis on knots in 3-manifolds). He then moved to Oxford for a postdoc (on knots & 4-manifolds). Daniele arrived in Australia in 2022 for another postdoc in Melbourne (knots & geometry), and he then moved to UQ as a lecturer last January.