The Universe is 13.75 ± 0.11 billion years old. Modern cosmology traces history backward in time to the first microsecond after the Big Bang. We have direct observational evidence up until the surface of last photon scattering, corresponding to when the Universe, at about 380,000 years of age, initially became transparent to radiation, and inferential evidence of prior epochs. But the central enigmas of cosmology — how did the Universe begin? and why is the world as it is? — surely among the first scientific queries posed by our human forbears — remain unanswered. These questions are so challenging precisely because they are also so basic. Unlike most other problems in physics, they reside at the crossroads of quantum theory and gravitation. In order to address them, we require a foundational understanding of fundamental aspects of cosmology. My research concentrates on non-perturbative issues in quantum gravity and strives to develop the language in which these rudimentary and ancient mysteries may be resolved.
String theory is the leading candidate for a theory of quantum gravity. My interests are broad, but focus on bringing string theory into contact with the real world. In particular, motivated by the AdS/CFT correspondence and the principle of holography, I strive to formulate the theory of statistical mechanics that underlies gravitational thermodynamics. Black holes supply an important theoretical laboratory for this research. I want to apply the technology developed in the black hole context to the resolution of spacetime singularities, especially in time dependent, cosmological backgrounds. I aim to understand holography and the emergence of spacetime in general settings. Another major thrust of my research is to explain how the Standard Model of particle physics descends from a fundamental theory. I seek to relate geometrical aspects of the vacuum space of quantum field theories to string theory and use geometric structure as a practical tool for particle phenomenology. Recently, I have been investigating the constraints on string compactifications stemming from cosmology and particle theory inputs. As well, I work on supersymmetric field theories in four dimensions and various problems in mathematical physics.
My work is supported by the South African Research Chairs Initiative of the Department of Science and Technology and the National Research Foundation. I am a Senior Investigator on the United States National Science Foundation grant CCF-1048082, “CiC (SEA-EAGER): A String Cartography.”
We have post-doctoral openings. Please apply via Academic Jobs Online.
I believe that learning and sharing insights about the mechanisms of Nature are each vitally important and that research and teaching are indivisible. I take both aspects of scholarship seriously. I apply the methodology of research to the classroom and seek to bring the same clarity of exposition that we have for old ideas to new ones. I expect students to engage with learning and assume an active role in their own education.
Cosmology (honors), 3rd/4th teaching blocks, 2012
Topics to be covered to some degree and in some order include: the large-scale structure of spacetime, the Friedmann–Robertson–Walker Universe, equations of state, the cosmological constant, dark matter, the age of the Universe, the cosmic microwave background, the hot Big Bang, inflation, Big Bang nucleosynthesis, structure formation, the future history of the Universe, and observational cosmology. In addition to problem sets and the examination, students will be evaluated on a course project.
I have a Masters student Simon Moolman. I may also take a Ph.D. student in 2012. In addition, I have a bursary for an honors undergraduate. If you are interested in pursuing studies under my supervision, please e-mail me.