PIRSA:11030110

Imperfect Dark Energy of Kinetic Gravity Braiding

APA

Vikman, A. (2011). Imperfect Dark Energy of Kinetic Gravity Braiding. Perimeter Institute for Theoretical Physics. https://pirsa.org/11030110

MLA

Vikman, Alex. Imperfect Dark Energy of Kinetic Gravity Braiding. Perimeter Institute for Theoretical Physics, Mar. 03, 2011, https://pirsa.org/11030110

BibTex

          @misc{ scivideos_PIRSA:11030110,
            doi = {10.48660/11030110},
            url = {https://pirsa.org/11030110},
            author = {Vikman, Alex},
            keywords = {Cosmology},
            language = {en},
            title = {Imperfect Dark Energy of Kinetic Gravity Braiding},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2011},
            month = {mar},
            note = {PIRSA:11030110 see, \url{https://scivideos.org/pirsa/11030110}}
          }
          

Alex Vikman New York University (NYU)

Talk numberPIRSA:11030110
Source RepositoryPIRSA
Talk Type Scientific Series
Subject

Abstract

In this talk I will discuss a new class of cosmological scalar fields. Similarly to gravity, these theories are described by actions linearly depending on second derivatives. The latter can not be excluded without breaking the generally covariant formulation of the action principle. Despite the presence of these second derivatives the equations of motion are of the second order. Hence there are no new pathological degrees of freedom. Because of this structure of the theory the scalar field kinetically mixes with the metric without direct non-minimal couplings to curvature - the phenomenon we have called Kinetic Gravity Braiding. These theories have rather unusual cosmological dynamics which is useful to model Dark Energy and Inflation. I will discuss an equivalent hydrodynamical formulation of these theories and cosmological applications.