PIRSA:11110077

Spatially Covariant Theories of a Transverse, Traceless Graviton

APA

Miller, G. (2011). Spatially Covariant Theories of a Transverse, Traceless Graviton. Perimeter Institute. https://pirsa.org/11110077

MLA

Miller, Godfrey. Spatially Covariant Theories of a Transverse, Traceless Graviton. Perimeter Institute, Nov. 15, 2011, https://pirsa.org/11110077

BibTex

          @misc{ pirsa_11110077,
            doi = {10.48660/11110077},
            url = {https://pirsa.org/11110077},
            author = {Miller, Godfrey},
            keywords = {Cosmology},
            language = {en},
            title = {Spatially Covariant Theories of a Transverse, Traceless Graviton},
            publisher = {Perimeter Institute},
            year = {2011},
            month = {nov},
            note = {PIRSA:11110077 see, \url{https://pirsa.org}}
          }
          

Godfrey Miller University of Pennsylvania

Abstract

General relativity is a covariant theory of two transverse, traceless graviton degrees of freedom. According to a theorem of Hojman, Kuchar, and Teitelboim, modifications of general relativity must either introduce new degrees of freedom or violate the principle of general covariance. In my talk, I will discuss modifications of general relativity that retain the same number of gravitational degrees of freedom, and therefore explicitly break general covariance. Motivated by cosmology, the modifications of interest maintain spatial covariance. Demanding consistency of the theory forces the physical Hamiltonian density to obey an analogue of the renormalization group equation, which encodes the invariance of the theory under flow through the space of conformally equivalent spatial metrics.