Research Fellows Directory
Dr Harvey Reall
University of Cambridge
I work on General Relativity (GR), Einstein's theory of gravity, with the extra spatial dimensions required by string theory. The main motivation for this is the "gauge/gravity correspondence", which relates higher-dimensional GR to certain non-gravitational theories in 3d. These theories are similar to theories governing particle physics, and even certain condensed matter physics systems such as superconductors. They are strongly interacting theories, which makes them difficult to study directly; the gauge/gravity correspondence gives a new way of understanding them using higher-dimensional GR. Black hole solutions of GR correspond to non-zero temperature states in the non-gravitational theory. Hence the study of higher-dimensional black holes may lead to a better understanding of finite temperature effects in strongly interacting theories. This could include the transition of a material between a "normal" and a superconducting state, and perhaps even lead to understanding of on high temperature superconductivity, which is believed to be a strongly coupled problem. This is clearly of great importance for applications.
Higher-dimensional black holes can exhibit much richer behaviour than 3d ones. My work concerns trying to understand what kinds of black hole can exist in higher dimensions, and to determine their stability (which is directly relevant to the phase transition mentioned above). The methodology involves developing new techniques for solving the equations of higher-dimensional GR.