Academics

Learn about the research I do when I’m not capturing ancient light

My Research

My research programme has two distinct thrusts. The first addresses one of the most important problems in modern Cosmology: the nature of the gravitational action and how changing it could provide a solution to the dark energy and dark matter problems. General Relativity (GR) is one of the cornerstones of modern physics. It describes in mathematical terms how matter causes space- time to curve, and therefore how objects in the universe move in a gravitational field. In particular it provides the foundations on which the standard model of cosmology is built. This picture has been tremendously successful, however, in order to explain the observational data, the matter in the universe must be dominated today by two mysterious dark components (dark matter and dark energy), in fact visible matter such as stars, planets and people accounts for just 4% of the total content of the universe. For many physicists this represents a major problem. In a nutshell, if GR is correct, we understand the dynamics of the universe but do not have a good understanding of what it is made of. This has lead researchers to consider the possibility that the gravitational action needs to be modified on large scales, removing the need for dark matter and/or dark energy. An extensive research programme in this area is under way at the University of Cape Town, involving collaborators from Italy, Spain and the UK.

The second thrust investigates the interface between GR and Plasma Physics in general and the coupling between gravitational waves and electromagnetic fields, expected to occur in extreme astrophysical environments in particular. When a gravitational wave (GW) passes through a magnetic field, it vibrates the magnetic field lines, creating electromagnetic (EM) radiation. Although this effect has been known for some time it remains a relatively unexplored area of physics. Virtually all stars have a strong magnetic field threading through and surrounding them. This field becomes immensely strong as the field lines are compressed as the star collapses to a Black Hole or neutron star. At many points in their lifetimes highly dense objects are powerful generators of GW, making them prime candidates for regions of the universe where the EM-GW interaction takes place to a significant degree. Initial investigations of the EM-GW interaction have provided indications of the physical processes we might expect. However, these effects have not yet been studied in a strong gravitational field, the most promising place where such an interaction is likely to happen. Since plasma physics in strong gravitational fields is known to have an extraordinarily complex set of modes and instabilities, this area is a fascinating and beautiful area of interdisciplinary research. 

My Publications

Visit my Inspire link to find the list of all my publications

Teaching

Teaching forms an important and challenging part of my activities and I enjoy interacting with students at all levels. My first and second year classes have provided me with an opportunity to experiment with the use of technology in the classroom. The Web as a delivery tool for course-work material has been particularly useful both as a way of enhancing understanding and providing me with an efficient way of monitoring students progress.

For example in my second year advanced calculus course, students are continually assessed via a series of on-line multiple choice problem sheets which give me instant feedback on how the students are coping with a particular topic. I regularly use computer algebra systems, and numerical simulations in classroom demos to give  a different perspectives on mathematical problems, providing a much needed link to situations of importance in everyday life.

Supervision

Graduation Day. Always a very special and immensely proud moment. Postgraduate supervision and training is a key component of my academic life. Over the past decade I have successfully developed an integrated research programme involving, graduate students, postdocs and international collaborators, many of whom are involved in research projects linked to bilateral agreements between South Africa, Sweden, Italy, Spain and the UK. This has provided a vibrant research atmosphere for my students who regularly interact with colleagues here and abroad. On finishing their degrees many of of students have obtaining prestigious PhD and postdoctoral scholarships and several former students are now senior academics at South African Universities.

Current Students

Mariam Campbell

MSc with distinction (2019)
PhD Student

Kelly MacDevette

PhD Student

Charlotte Louw

MSc Student

Jess Worsley

MSc Student

Jenna Bruton

MSc Student

Vineshree Pillay

MSc Student

Maria-Alexia Caldis

MSc Student

Past Students

Avishek Dusoye

PhD (2022)

Sulona Kandhai

MSc (2013), PhD (2019)

Tim Oreta

MSc (2015)

Shreef Nasser

MSc (2014)

Bishop Mongwane

PhD (2014)

Tjaart de Wit

MSc (2013)

Amare Abebe Gidelew

MSc (2009), PhD (2013)

Anne Marie Nzoki

MSc with distinction (2009),
PhD (2013)

Mohamed Elshzli Sirelakhtim

MSc with distinction (2008),
PhD (2013)

Pieter Conradie

MSc (2012)

Maye Elmardi

MSc (2010)

Jannie Leach

PhD (2008)

Bob Osano

PhD (2008)

Caroline Zunckel

MSc with distinction (2005)

Naureen Goheer

PhD (2005)

Antony Millner

MSc with distinction (2005)

Bonita de Swardt

MSc with distinction (2004)

Deon Solomons

PhD (2003)

Alexander Kahle

MSc with distinction (2003)

Stacey Hobbs

MSc with distinction (2001)