Séminaire

In recent years, multiple lines of evidence have emerged supporting the idea that Be stars are mass gainers in interacting binaries. Together, these findings suggest a compelling scenario in which all Be stars are formed through binary interactions. Nevertheless, the broader implications of this scenario must be carefully examined within the context of massive binary evolution.

Cosmological correlators encode the signatures of the universe's evolution, and by measuring correlations in the late universe we infer the dynamics and contents of the universe. I will review some recent developments in the study of the structure of quantum field theory in curved spacetimes, and the computation of cosmological correlators.

The experimental quest to extract the full information content of the anisotropies of the Cosmic Microwave Background (CMB) has lead to a Moore's Law-like evolution in instrument capabilities. In this seminar, I explore adapting the technologies developed for the CMB to two other, more challenging science goals: Spectral Distortions, and Intensity Mapping.   I will discuss these science topics and present concepts for instruments that could make precise measurements of these signals. I present the SPECTER instrument concept.

DESI is the first new generation galaxy survey to take data with the goal to shed light on the mechanism that drives the acceleration of the cosmic expansion. We postulate the existence of a mysterious component, dark energy, responsible for such acceleration, and we assume, in our current cosmological model, that dark energy takes the form of a cosmological constant Lambda.

The QCD axion, a fascinating hypothetical particle proposed about 50 years ago, might hold the key to explaining one of the universe’s lingering mysteries: why strong interactions don't seem to break CP symmetry. Perhaps more importantly, it remains one of the most exciting dark matter candidates. 

What would we give to see an even younger image of the Universe from relics of the Big Bang?  And how can one even imagine how to do that?  One of the most subtle and important discoveries in elementary particle physics was to find that the tiny neutral particles that Enrico Fermi called the neutrinos have mass.  This mass was discovered indirectly through an effect predicted by Bruno Pontecorvo, now probed to high precision by KM3Net.