Weyl-Invariant Einstein-Cartan Gravity: Unifying the Strong CP and Hierarchy Puzzles

This special seminar explores how Weyl-invariant Einstein-Cartan gravity, when combined with the Standard Model of particle physics, reveals a unified approach to solving both the strong CP and hierarchy puzzles. Learn how this theoretical framework introduces just one extra scalar degree of freedom with axion-like properties that addresses the strong CP-problem. Discover how the small mass of this particle and the cosmological constant are related to tiny values of gauge coupling constants of the local Lorentz group. Examine the implications for the Higgs boson mass and Majorana leptons, which appear to be very small or vanishing at tree level, suggesting potential computability through nonperturbative effects. The presentation by Misha Shaposhnikov from EPFL offers insights into this elegant theoretical approach that connects fundamental problems in particle physics and cosmology.