The Hubble tension and self-interaction cross section of dark matter from JWST observations of lensed quasars

by Tommaso Treu (UCLA)

Thursday 8 Oct 2026, 11:30 → 12:30 Europe/Rome

Sala Jappelli (Osservatorio astronomico di Padova)

I will present new cosmological results based on  strongly lensed quasars. First, I will report on recent progress in using gravitational time delays (via the TDCOSMO collaboration) to measure the Hubble constant independently of both the local distance ladder and the cosmic microwave background. Using JWST-NIRCam and NIRSpec, we have now reached 3% precision, offering new insights into the Hubble tension.  Second, I will describe recent results based on flux ratio anomalies measured with JWST-MIRI.  I will show new limits on the dark matter free streaming length and hint of ultradense halos that may be explained by dark matter having a non-zero self-interaction cross section. 

 

Join Zoom Meeting  

 

https://unipd.zoom.us/j/5828340760?pwd=6jmmfQkNz1qXnnOzaEWzo9kuEunbhb.1 

 

Meeting ID: 582 834 0760
Passcode: Npsvx4