PhD ceremony Mr. Y. Yin: Extensions of three-dimensional higher-derivative gravity

PhD ceremony: Mr. Y. Yin, 12.45 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Extensions of three-dimensional higher-derivative gravity

Promotor(s): prof. E.A. Bergshoeff, prof. M. de Roo

Faculty: Mathematics and Natural Sciences

The three-dimensional higher-derivative gravity models, in particular the New Massive Gravity (NMG) and the Topologically Massive Gravity (TMG), are toy models used by theoretical physicists to investigate how to improve Einstein’s general theory of relativity. This thesis aims at a better understanding of the theoretical framework of NMG and TMG, by investigating whether they can be extended to a larger set of models.

NMG and TMG are models in three-dimensional spacetime that contain spin-2 particles. This thesis shows that, when spacetime is almost flat and gravity is weak, the approximate models of NMG and TMG can be extended to describe many more types of particles, including spin-1, spin-3/2, spin-2, spin-5/2, and so on. This thesis also shows that in some situations the models of these particles can be further extended to spacetime dimensions larger than three. Moreover, the three-dimensional models of spin-2 and spin-3/2 can be combined into a type of model called supergravity, which is also discussed in the thesis. The thesis concludes that, at least for the approximate models, NMG and TMG can indeed be extended to a much larger framework of models.