College of Agriculture, Engineering
and Science (CAES)

Mathematician and Teacher Takes Einstein’s General Relativity to the ‘Next Level’ at Virtual Inaugural Lecture

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A senior member of UKZN’s Astrophysics Research Centre and a full professor in the School of Mathematics, Statistics and Computer Science, Professor Sudan Hansraj, is the first academic at the University to present his official inaugural lecture online.

COVID-19 restrictions resulted in the virtual presentation and Hansraj used the opportunity to elaborate on his field of academic expertise – taking Einstein’s theory of general relativity to the next level.

‘Einstein’s celebrated general relativity (GR) is the most successful theory of the gravitational field,’ said Hansraj. ‘It generalised Newton’s theory through a novel understanding of gravity as a geometrical effect being the curvature of spacetime.

‘General relativity, propounded as a mathematical theory, has since passed numerous experimental tests within the solar system prompting some to believe it is universally applicable. On the other hand, general relativity fails to explain the observed accelerated expansion of the universe without invoking exotic forms of matter and it has yet to be tested in strong gravity regimes such as those external to black holes and neutron stars.’

Hansraj believes that the time is ripe for a geometrical modification of general relativity without compromising its victories.

His lecture expounded on his research, which has explored a variety of modified field theories and has focused heavily on Lovelock gravity and its special case, Gauss-Bonnet gravity, as successors to general relativity.

Labelling himself a ‘late starter’ in research, Hansraj has nevertheless published about 50 papers on Einstein’s general theory of relativity and its extensions, both as lead author and single author, including a significant percentage in high impact journals. He is a reviewer for more than 18 international journals and was given an Outstanding Reviewer Award by the journal Classical and Quantum Gravity (IF 3, 49) in 2020. He has also participated in about 58 international and local conferences and is presently chair of the local organising committee of Gravitex 2021: International Conference on Gravitation – Theory and Experiment, to be held online.

To date, Hansraj has graduated three PhD and eight master’s students in Applied Mathematics and has supervised two postdoctoral fellows. He is an NRF C-rated researcher.

Why study gravity? ‘Gravity helps us understand how big things in the universe work,’ said Hansraj. ‘It is in the spirit of humanity to find answers to deep questions. When one answers some of the deep questions of Science, one can advance in other areas.’

A successful academic, Hansraj is also known for his commitment to the teaching of mathematics. He started his working life in 1987 as a high school teacher of mathematics after obtaining a teaching diploma from Springfield College – a standard route for scholastic high achievers of low economic means in marginalised communities at that time.

Bachelor and Honours degrees in Pure Mathematics from UNISA followed as well as an MSc and PhD from the then University of Natal (NU) under the supervision of Professor Sunil Maharaj. In 2002, Hansraj moved from Durbanse Onderwyskollege (Dokkies) where he was lecturing in Mathematics Education to join its sister department on the Edgewood Campus of NU as a senior lecturer, before being transferred shortly thereafter to the Mathematics department.

More than 30 years later, Hansraj still views himself as a teacher at heart. ‘I consider the teaching of mathematics to be one of my most important contributions,’ he said. Hansraj pioneered the infusion of technology in university mathematics teaching and proudly notes that he taught classes across the board from first-year to honours level as well as mathematics service classes for Engineering students.

In 2017 he was awarded a Distinguished Teacher award by the College of Agriculture, Engineering and Science.

‘I still rate my teaching achievements as a high school teacher in the matriculation examinations as the highlight of my teaching career,’ he said.

Hansraj has made extensive contributions to the wider community of mathematics. He was a founding member of the South African Mathematics Foundation (SAMF) and has served on Mathematics Olympiad committees for many years, co-authoring two books for use by high school learners in preparing for contests on creative problem solving. He has also devised a teacher development programme that ran for about 15 years training teachers through the SAMF on how to tackle Olympiad problems; coached the South African Mathematics Olympiad team; was team leader to the Pan African Mathematics Olympiad and Hong Kong Olympiads, and acted as a jury member of the International Mathematics Olympiad hosted by South Africa.

Currently Hansraj is a three-term member of the Assessments Standards Committee of the UMALUSI Council.

At UKZN, Hansraj served as the Academic Leader for Mathematics and was elected by College academics as their representative on the Institutional Forum (IF) where he served for many years, including as Chair. During his tenure he made successful representations to the Council to increase the retirement age at UKZN to 65.

Words: Sally Frost

Photograph: Supplied