Space-Time Foliation in Quantum Gravity

In this thesis, the author considers quantum gravity to investigate the mysterious origin of our universe and its mechanisms. He and his collaborators have greatly improved the analyticity of two models: causal dynamical triangulations (CDT) and n-DBI gravity, with the space-time foliation which is one common factor shared by these two separate models. In the first part, the analytic method of coupling matters to CDT in 2-dimensional toy models is proposed to uncover the underlying mechanisms of the universe and to remove ambiguities remaining in CDT. As a result, the wave function of the 2-dimensional universe where matters are coupled is derived. The behavior of the wave function reveals that the Hausdorff dimension can be changed when the matter is non-unitary. In the second part, the n-DBI gravity model is considered. The author mainly investigates two effects driven by the space-time foliation: the appearance of a new conserved charge in black holes and an extra scalar mode of the graviton. The former implies a breakdown of the black-hole uniqueness theorem while the latter does not show any pathological behavior.

Provides a pedagogical review of two quantum gravity models: causal dynamical triangulations, with the aid of numerous illustrations, and n-DBI gravity Contains many examples of and supplements to the analytic method for computing the wave function of the Universe in 2-dimensional CDT Nominated as an outstanding Ph.D. thesis by Nagoya University's Physics Department in 2013 Includes supplementary material: sn.pub/extras

Autorentext
Dr.Yuki Sato
Nagoya University
Department of Physics
Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan

Inhalt
Introduction.- Causal Dynamical Triangulation.- n-DBI Gravity.- Summary.- Appendices.