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Physicists on a quest

- By Wits University

It will be 100 years next year since Albert Einstein published his theory of general relativity in 1915. Still, many questions remain unanswered and one of physics greatest quests – to find a satisfactory theory for quantum gravity – is bringing together some of the world’s leading researchers in the field at the Joburg Workshop on Matrices, Holography and QCD, next week.

Jointly organised by Wits and Brown Universities, with support from the National Institute for Theoretical Physics and hosted by the Wits Centre for Theoretical Physics (CTP), the annual workshop will take place next week from Monday to Friday (15 – 19 December 2014 at the School of Physics, Wits University, Braamfontein Campus East, Johannesburg).

For well over 30 years, particle physicists have been trying to understand why quarks – the basic building blocks of matter – are confined into twos and threes and are never observed isolated in nature. Quantum Chromodynamics (QCD) – the theory of the strong interactions responsible for binding neutrons and protons in the nuclei of atoms should be able to explain not only the confinement of quarks but also predict the masses of strongly interacting particles.

“Despite many attempts over several decades, this has not been satisfactorily achieved. Insights from string theory have recently suggested that it may be possible to achieve this in terms of a gravitational description in a curved background. This curved background has one dimension more than our space-time, which is then a hologram!” says Professor Joao Rodrigues, head of the Centre for Theoretical Physics (CTP), a unit in the Wits School of Physics that includes the leading string theory group on the continent.

A link between particle physics (QCD) and Einstein’s general relativity is unexpected, and is one of the most exciting areas of current research in Theoretical High Energy Physics, and the subject of active research carried out by the CTP.

To further enhance the CTP’s contribution and research capacity, Rodrigues says the University’s Research Committee has approved a change of status for the CTP to that of an Institute that will from January 2015 be known as the Mandelstam Institute for Theoretical Physics – named after the eminent South-African born American theoretical physicist and Wits graduate, Stanley Mandelstam, Professor Emeritus at University of California, Berkeley.

Mandelstam made seminal contributions to Particle Physics and String Theory. Today, in any particle collision – such as those collisions set off by the Large Hadron Collider at the European Organization of Nuclear Research (CERN) in Geneva, Switzerland – the energies and momenta of the reactions are described by what have become known as the Mandelstam variables that naturally incorporate Einstein’s theory of special relativity. Mandelstam also made crucial contributions to string theory, formulating string theory in terms of a quantum field theory on surfaces, and being the first to obtain string scattering amplitudes.


The Wits School of Physics has a decades-long collaborative research relationship with Brown University specifically in Theoretical High Energy Physics and this is the first year Brown is co-organising the Joburg Workshop.

The workshop, presented for the fifth consecutive year, is funded by the National Institute for Theoretical Physics that has its Gauteng node based at the Wits Centre for Theoretical Physics (Mandelstam Institute for Theoretical Physics). The aim is to bring eminent physicists to South Africa to share their research with local physicists and provide specialised training for post-graduate students.

Prominent physicists from Stanford University (US), the Tata Institute (India), the Wigner Institute (Hungary), Porto (Portugal), Andres Bello (Chile), Wits (SA) and Brown (US) Universities and researchers from several institutions in South Africa and Europe will be the speakers at this year’s workshop.