Was Einstein Right Handed?

          @misc{ pirsa_PIRSA:09110132,
            doi = {10.48660/09110132},
            url = {https://pirsa.org/09110132},
            author = {Alexander, Stephon},
            keywords = {Cosmology},
            language = {en},
            title = {Was Einstein Right Handed?},
            publisher = {Perimeter Institute},
            year = {2009},
            month = {nov},
            note = {PIRSA:09110132 see, \url{https://pirsa.org}}
          }
          

Abstract

Of all four forces only the weak interaction has experimentally exhibited parity violation. At the same time observations suggest that general relativity may require modification to account for dark matter and dark energy. Could it be that this modification involves gravitational parity violation? Many of the dominant approaches to quantum gravity, such as string theory and loop quantum gravity, point to an effective parity violating extension to general relativity known as Chern-Simons General Relativity (CSGR). In this colloquium I will discuss the uniqueness and phenomenological implications of parity violation in CSGR. In particular, I will discuss how CSGR can work together with inflation to generate the cosmic baryon asymmetry in a most economical fashion, through gravitational waves; and its predictions for upcoming CMB polarization experiments. I will also discuss current predictions of CSGR on binary pulsars, neutron stars and prospects for the LISA/LIGO gravitational wave detectors. While we focus on a specific theory for concreteness, some of the results presented in this colloquium can be seen as model independent.