Théorie

Warm Inflation is a variant inflationary scenario where the inflaton field continuously dissipates its energy to a subdominant radiation bath during inflation. Among the many advantages that WI has over its more standard counterpart, which we will refer to as Cold Inflation, is that WI smoothly transits to a radiation dominated Universe post inflation without invoking the need of a reheating phase, dynamics of which is still quite unknown. The dissipation effects effective during Warm Inflation makes the dynamics of the inflation quite intricate. Even the simple graceful exit in Cold Inflation turns out to be not so simple in Warm Inflation. In this talk, we will do the background analysis of Warm Inflation and shed light on how Warm Inflation ends or gracefully exits. These graceful exit criteria also constrain the form of the potential and the dissipative coefficients that one may choose for their Warm Inflationary model. Moreover, it indicates whether Warm Inflation can at all exit to a radiation dominated epoch or not.

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 Alpha Magnetic Spectrometer (AMS) is a general purpose high energy particle detector, which was successfully deployed on the International Space Station on May 19, 2011. It conducts a unique, long-duration mission of fundamental physics research in space. To date, the detector has collected over 255 billion cosmic ray events. This talk presents the latest AMS measurements of cosmic ray elementary particles. The latest results up to the energies of few Tera-electronvolts reveal distinctive properties of particle fluxes and indicate the existence of a primary source of high-energy electrons and positrons, associated with either Dark Matter or an Astrophysical origin. AMS is poised to continue its mission through 2030, providing unique insights into the origins of cosmic ray matter and antimatter and exploring new physics phenomena within the cosmos.

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.