Quasi-Local Mass, Positive Scalar Curvature and Positive Mass Theorem for Causal Variational Principles

Explore a 37-minute conference talk by Felix Finster on quasi-local mass, positive scalar curvature, and a positive mass theorem for causal variational principles. Delve into the introduction of causal variational principles and learn how a minimizing measure can be used to associate a non-negative quasi-local mass to a spatial region. Discover a synthetic definition of positive scalar curvature and understand how the quasi-local mass transitions to total mass when exhausting the whole space. Examine the connection between the mass of an asymptotically flat static spacetime and the construction of a static causal fermion system. Investigate the relationship between ADM mass and the total mass of the resulting causal variational principle. Follow the progression from introduction to general setup, minimizer, geometric interpretation, quasilocal mass, area, scalar curvature, spin geometry to causal variation, spin bundle, setting of causal systems, and the causal action principle in this comprehensive exploration of non-regular spacetime geometry.