IR Renormalizations of G_N, and the Cosmological Constant Problems

          @misc{ scivideos_PIRSA:10040041,
            doi = {10.48660/10040041},
            url = {https://pirsa.org/10040041},
            author = {Patil, Subodh},
            keywords = {Cosmology},
            language = {en},
            title = {IR Renormalizations of G_N, and the Cosmological Constant Problems},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2010},
            month = {apr},
            note = {PIRSA:10040041 see, \url{https://scivideos.org/pirsa/10040041}}
          }
          

Abstract

We discuss a candidate mechanism through which one might address the various cosmological constant problems. We observe that the renormalization of gravitational couplings manifests non-local modifications to Einstein's equations as quantum corrected equations of motion, and in doing so offers a complimentary realization of the degravitation paradigm-- a realization through which its non-linear completion and the corresponding modified Bianchi identities are readily understood. We proceed to consider theories whose coupling to gravity might a priori induce non-trivial RG flow for gravitational couplings in the IR, and arrive at a class of non-local effective actions which yield a suitably degravitating filter function for Newton's constant upon subsequently being integrated out.