The distance duality relation: violations, constraints and biases

Marzo 24, 2022
De 3:00pm hasta 4:00pm

Online on Zoom

Specialist level
Speaker: 
Natalie Hogg
Institution: 
IPhT Paris-Saclay
Location&Place: 

Online on Zoom

Abstract: 

We live in the era of precision cosmology, but how can we be sure that we are not losing out on accuracy and becoming susceptible to bias when striving for ever-greater precision in our cosmological measurements? To illustrate this question, in this talk I will present forecast BAO, SNIa and standard siren constraints on a violation of the strict relationship between luminosity and angular diameter distances, known as the distance duality relation (DDR). I will show how such constraints can be biased in the presence of a generic modified gravity model and how such a bias can be correctly accounted for in similar analyses. I will then go on to show how, in combination with Hubble's law, the distance duality relation can be used as a consistency check for beyond-LCDM cosmological models, revealing a 2σ discrepancy between the validity of the DDR and the latest Cepheid-calibrated SNIa measurement of H0.

Zoom link: https://zoom.us/j/91390797603?pwd=bWdEdUJNYkhZQWZQRFdsTjlSQXk0Zz09