Dartmouth Events

Abstract: Motivated by the observed excess of Fermions with left-handed chirality in our universe, we use the mixed gauge-gravitational anomaly in universes which contain primordial gravitation waves as a preferential source for Fermions with a particular handedness. In order to create the necessary source of polarized gravitation waves, we examine spacetimes with an intrinsic handedness. The Bianchi spacetimes are a widely studied class of spatially homogeneous but anisotropic spacetimes, several of which admit descriptions as polarized gravitation waves superposed on an FRW background. Of particular interest is Bianchi IX, a generalization of the spherical FRW universe with a longest wavelength circularly polarized gravity waves of a single handedness wrapped around it.