Plenary speakers

Swantje Bargmann
Prof Swantje Bargmann
(University of Wuppertal, Germany)
Title: TBC

Bio: Swantje Bargmann is a full professor at University of Wuppertal in Germany; after having hold a full professor position at TU Hamburg (jointly with Helmholtz-Zentrum Hereon), an assistant professor position at TU Dortmund as well as guest professor positions at Chalmers University (Sweden) and University of Cape Town (South Africa). She studied mathematics at TU Kaiserslautern, where she also completed her doctorate in 2008. Her research work focuses on mathematical modeling of material behavior of solids and has received several awards, e.g Heinz Maier-Leibnitz Prize (DFG), Richard von Mises Prize (GAMM), Science Prize (Industrieclub Düsseldorf), Scientific Prize (Esaform) as well as scholarships from e.g., Japan Socienty for the Promotion of Science, National Research Foundation of Korea and Heinrich-Hertz-Foundation.

Bengt Fornberg
Prof Bengt Fornberg
(University of Colorado Boulder, USA)
Title: TBC

Bio: Prof Bengt Fornberg's main research interests are in developing, analyzing, and implementing numerical methods, in particular for solving PDEs to high orders of accuracy. Such methods include pseudospectral and high accuracy finite difference methods, and methods based on radial basis functions (RBFs). Their main application areas include computational fluid dynamics, geophysical and astrophysical flows, and seismic exploration. Another interest area is computational methods in the complex plane (such as for solving the Painlevé equations, and for more general quadrature and differentiation).

Natasha FLyer
Prof Natasha Flyer
(University of Colorado Boulder, USA)
Title: Nuances of Machine Learning Algorithms for Rare Event or Sparse Data

Bio: Natasha Flyer's background is in applied/computational mathematics and algorithm development directed towards the solar/geo-sciences, specifically for forecasting natural events. Her specialty is to create new mathematical techniques that can be easily customizable for computational applications in the above-mentioned fields. Her collaborations and business interactions have included working with space weather forecasters, climate modelers, meteorologists, oceanographers, and solid Earth geophysicists. She was a scientist in the Computational and Information Systems Lab at the National Center for Atmospheric Research for over 20 years. She currently runs her own professional consulting firm and is an Adjunct Professor at the University of Colorado, Boulder, Dept. of Applied Mathematics.

Sudan Hansraj
Prof Sudan Hansraj
(University of KwaZulu-Natal)
Title: Numerical techniques in the mathematics of gravitational
Abstract: The gravitational field remains the most mysterious of the four fundamental forces in nature. The general theory of relativity (GR) built from the Einstein-Hilbert lagrangian is the most successful theories of gravity to date. Nevertheless, it has a number of serious shortcomings necessitating modifications. Currently GR relies on the possible existence of exotic matter for which no support has emerged to date. However, a different school of thought works on extending the geometrical sector to accommodate what is actually observed. As a consequence a number of modified theories have emerged in the recent past in an effort to succeed GR. Each of these must also pass basic tests such as diffeomorphism and Lorentz invariance and the Bianchi identities. When GR is applied to construct models of stars, a coupled system of 10 nonlinear partial differential equations arises in general in four dimensions. The number reduces to 3 if spherical symmetry is assumed however in the case of isotropic or perfect fluid matter field there are 4 unknowns. This means that an extra closure condition must be stipulated. The most important physical constraint that could be imposed is an equation of state relating two of the variables. The caveat is that the master differential equation is not solvable exactly for physically relevant cases. Numerical schemes must be implemented to reveal the characteristics of the gravitational field. Ad hoc assumptions on some of the dynamical variables may also be made for mathematical expediency however the likelihood of the solution satisfying an equation of state is slim. Some 120 exact solutions have been reported over the past century. Of these only fewer than 10 tick all the boxes for physical acceptability. The trade-off going down the numerical route, on the other hand, is that while the dynamics may be understood to high degrees of accuracy, the geometry in the form of the metric remains unknown. In this talk we shall discuss the umerical schemes employed to solve the Tolman-Oppenheimer-Volkoff equation which emanates from the conservation laws also known as the condition for hydrodynamical stability or continuity equation. This equation follows from the 3 field equations however it may substitute any one. The system has precisely 3 independent equations. We will examine how the mass-radius relations can be found using numerical techniques. Finally we shall comment on how the latest information coming from the Nobel-prize winning work on gravitational waves can be used in the study of stellar structure.

Bio: Sudan Hansraj is professor of applied mathematics at the University of KwaZulu-Natal, Durban, South Africa. His research area is Einsteins general theory of relativity and its modifications. He belongs to the school of thought that espouses correction to the action namely the geometric sector of the standard theory to address its shortcomings such as inability to explain the late-time accelerated expansion of the universe without an appeal to exotic matter. He has published some 85 research articles almost 80% in the Q1 category (top 25% in the field) including 8 in the celebrated Physical Review D. He is an NRF rated researcher and has featured in the Standford University ranking of the top 2% of scientists in the world regularly. He is an elected Fellow of the Royal Astronomy Society (UK). Some of his visiting international appointments include: University College London, University of Milan, University of Rio de Janeiro, Chinese University of Hong Kong, Universite de Paris 7th, Inter-University Centre for Astronomy and Astrophysics India, Jamia Milia University India, IESER Kolkata, India; Niels Bohr Institute Copenhagen. He has participated in over 80 local and intenational conferences with 5 Plenary/ keynote Talks. At UKZN he served as an Academic Leader Mathematics (5 years) and chair of the Institutional Forum – a statutory structure tother with the Senate and Council. On the national scence he has been worked with the South African Mathematics Olympiad since 1996 and has served as an IMO jury member. He is a founding member, SA Mathematics Foundation (SAMF) and is currently president of the South African Gravity Society. Prof Hansraj has aalso served the nation on the UMALUSI Council Standardisation Committee for 16 years.

Dephney Mathebula-Periola
Prof Dephney Mathebula-Periola
(University of Fort Hare)
Title: TBC

Bio: Prof Dephney Mathebula-Periola is a Full Professor of Mathematics at the University of Fort Hare and the first South African to obtain a PhD in Mathematics from the University of Venda. Her research focuses on Biomathematics, particularly on the mathematical modelling of infectious diseases. She has presented her work at international and local conferences and published extensively in high-impact journals. Prof Mathebula-Periola was honoured with the 2025 Mail & Guardian Power of Women Award in the STEMi category and recognised among the Top 100 Career Women in Africa (2024) for her remarkable contributions to science, leadership, and mentorship. She is passionate about advancing women in STEM and nurturing the next generation of African scientists.

Paul Milewski
Prof Paul Milewski
(Penn State University, USA)
Title: TBC

Bio: Prof Paul Milewski is Professor and Head of the Department of Mathematics at Pennsylvania State University, USA. He works in applied mathematics with a focus on nonlinear waves, fluid mechanics, and computational modelling. After completing his PhD at MIT, he held positions at Stanford University and the University of Wisconsin–Madison before moving to the University of Bath, where he later served as Head of Mathematical Sciences. His research combines analytical and numerical approaches to understand complex wave phenomena in fluids and related systems. He is a recipient of the Alfred P. Sloan Research Fellowship and the Royal Society Wolfson Merit Award.

Precious Sibanda
Prof Precious Sibanda
(University of KwaZulu-Natal)
Title: TBC

Bio: Professor Precious Sibanda is an NRF-rated researcher and Professor of Applied Mathematics. He holds an MSc and PhD in Applied Mathematics from the University of Manchester. His research, spanning over 29 years focusses on theoretical and computational fluid dynamics, numerical methods, and mathematical biology. He is a dedicated mentor and has supervised numerous (over 50 MSc/PhD) postgraduate students. Professor Sibanda is an elected Member of the Academy of Science of South Africa (ASSAf) and a former Finamcial Manager and President of the South African Mathematical Society (SAMS). He has previously served as a SAMS representative on national bodies such as the South African National Committee for the IMU (SANCIMU)

Geoff Vasil
Prof Geoff Vasil
(University of Edinburgh, UK)
Workshop title: Lessons on solving nearly any equation using the Dedalus computational framework
Talk title: Sphere we go again: lessons on solving equations in curved spaces with polynomials and tensors 

Bio: Prof Vasil did his PhD in Geophysical and Astrophysical Fluid Dynamics at the University of Colorado. Before that, he studied mixtures of Pure and Applied Mathematics, and Theoretical Physics. He works on topics surrounding Physical Applied Maths, Fluid Mechanics, Plasma Physics, Solar Magnetohydrodynamics and Mathematical Computing.

Since 2012, he has been a founding core-team member of the open-source Dedalus project: http://dedalus-project.org

Recently, Dr Vasil has been expanding into new areas. On the more pure side, the rich geometric and combinatorial structures surrounding orthogonal polynomials and special functions (useful, e.g., for the computational framework underlying Dedalus). This includes applications to probability, combinatorics, optimisation and mathematical physics. Further on the applied side, Dr Vasil has been studying differential equations on networks with contiguous edges. This work has wide-ranging applications in mathematical biology and condensed matter physics.