Classically Consistent Theories of Interacting Spin-2 Fields
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
This doctoral thesis comprises a study of recently developed nonlinear theories for massive spin-2 fields that go by the names of Massive Gravity and Bimetric Theory. As we demonstrate in a Hamiltonian analysis, the construction of these theories avoids the notorious Boulware-Deser ghost instability that generically plagues nonlinear spin-2 interactions and renders their description inconsistent. We explore the mass spectrum of ghost-free Bimetric Theory and reformulate its action in terms of nonlinear mass eigenstates. A generalized version of the theory with multiple vielbein interactions is reviewed and then reexpressed in terms of metrics. Homogeneous and isotropic solutions to the equations of motion in Bimetric Theory are derived and discussed in the context of cosmology. We furthermore single out particular values for the parameters in the bimetric interaction potential for which the theory could potentially contain an additional gauge redundancy. This establishes a unique candidate for a nonlinear theory of a partially massless spin-2 field. Finally, we reveal a close connection of Bimetric Theory to a certain class of higher-curvature theories for gravity and offer a solution to their ghost problems. In particular we find that, in four space-time dimensions, the bimetric candidate for nonlinear partial masslessness is closely related to Conformal Gravity.
Place, publisher, year, edition, pages
Stockholm: Department of Physics, Stockholm University , 2013. , 134 p.
Research subject Theoretical Physics
IdentifiersURN: urn:nbn:se:su:diva-96167ISBN: 978-91-7447-791-7OAI: oai:DiVA.org:su-96167DiVA: diva2:663715
2013-12-12, sal FA32, AlbaNova Universitetscentrum, Roslagstullsbacken 21, Stockholm, 13:30 (English)
Deffayet, Cedric, Professor
Hassan, Fawad, Senior lecturer
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Submitted. Paper 6: Submitted. Paper 8: Manuscript.2013-11-202013-11-122013-11-12Bibliographically approved
List of papers