Disclaimer, emotional trigger: Six years ago, I attended the GR22/Amaldi 13 as a postdoc, my first year as a postdoc. One of the largest conferences on gravitational waves. At that conference, I delivered 2 talks: my last talk on continuous gravitational waves and my first talk on gravitational waves cosmology.

This year, I attended the GR24/Amaldi16 as the Principal Investigator of a new group focusing on gravitational wave cosmology. I chaired the Cosmology: Theory and observation session. I did not deliver any talk, but the PhD students and postdocs of my group did! It was a nice occasion to meet with colleagues for a lifetime, but also to discuss with new ones entering the field. It is incredible to witness how science and generations are progressing so quickly. I feel old already!

Let’s go to the science part now!

Sarah Ferraiuolo (PhD student) presented how the stochastic gravitational wave background can help to constrain the Hubble parameter, together with resolved sources.

Leonardo Iampieri (PhD student) presented a new method to estimate the Hubble constant with time delays between gamma-ray bursts and gravitational waves from binary neutron stars.

Gregoire Pierra (Postdoc) presented tentative evidence for a correlation between the spin magnitude and mass of black holes. Could this be the smoking gun for the presence of black holes formed dynamically in dense star clusters?

Top Figure: Me delivering my talk on Continuous Gravitational Waves at the GR22/Amaldi13 conference.
Bottom Figure: Me (in the middle of the picture), with the postdocs and PhD students of the Rome Virgo group. Not all of them are working on gravitational wave cosmology, but everybody is doing great science.