Astrofisica

# A Growing Universe... and Tension Is there any Signal For New Physics?

## by Ruchika Kaushik (IIT Physics Department, Bombay, India)

Europe/Rome
Aula Conversi (Dipartimento di Fisica - Ed. G. Marconi)

### Aula Conversi

#### Dipartimento di Fisica - Ed. G. Marconi

Description

Recent local measurements from SNe Ia using cepheids as calibrators shows that Hubble Tension now has been confirmed to more than $5 \sigma$ from the predictions using Cosmic Microwave Background at very high redshifts. Therefore now, we can completely give up the possibility of the idea that Hubble Tension is sole due to systematics. In this talk, I will first talk about Hubble Tension explaining briefly how low redshift (SH0ES) and high redshift (CMB) measurements of the Hubble Constant are taken or derived. I shall go on to show what constraints we get on H0 by combining all low redshift data like SNe Ia, Baryon Acoustic Oscillations, Time delay strong lensing, cosmic chronometers, and growth from different redshift bins. I will also raise a point to show that Early Dark Energy may not be enough to provide a solution for Hubble Tension. On the other hand, a G-transition well allowed by BBN and CMB bounds at very low distances can be a possible solutions in resolving the Hubble Tension. Also we see that a G-Transition hypothesis is preferred by the Cepheids and Supernovae data over no G-Transition while fitting for the distance ladder.

Organized by

Alessandro Melchiorri