Inaugural lecture sheds light on dark energy and why the theory of gravity is at a crossroads

On 14 July 2022, North-West University (NWU) professor in the subject group Physics, Prof Amare Abebe Gidelew, presented his inaugural lecture titled “Matters of Gravity: The how and why of cosmic evolution”. 

Prof Gidelew presented a brief account of one of humanity’s greatest adventures: trying to understand the origin, evolution, and ultimate fate of the universe we live in.

He showed that our understanding of the universe and the physical processes involved in its evolution has in itself evolved over time.

“This lecture illustrates that the most important of these physical processes is gravity, and aims to explain why our current understanding of the theory of gravitation is once again at a crossroads,” said Prof Gidelew.

“We have reason to believe that general relativity, the standard theory of gravitation, does not adequately describe the currently observed accelerated expansion of the universe.

“This accelerated cosmic expansion requires some form of repulsive gravity, dubbed ’dark energy’. Moreover, there is increasing observational evidence that most of the matter in the universe out of which large-scale structures (galaxies, clusters, and superclusters) are made exists in an invisible ‘dark matter’ form. This lecture sheds some light on some alternative solutions to the dark energy and dark matter problems through modifications in the gravitational theory,” he explained.

During his presentation, Prof Gidelew focused on some of his own research highlights in understanding the evolution of the universe through alternative gravitational theories, the scientific rationale behind this all, the collaborations and student supervisions involved in this endeavour, as well as future research envisaged.

He said his academic trajectory would not have been this smooth had it not been for the numerous individuals that positively contributed to his growth, both academically and personally.

“This includes my family, friends, colleagues, and mentors, without whom this inaugural lecture would have been but a distant possibility,” said Prof Gidelew.

Giving a congratulatory address, Prof Jeffrey Mphahlele, deputy vice-chancellor for research and innovation, said an inaugural lecture ceremony marks the rite of passage into the ranks of professorship.

“This recognition is no small feat. It is not just about courage and effort, but is also a combination of skill, endurance, and ingenuity. This is the highlight of your career and one of the greatest achievements worth celebrating.

“The presentation was illuminating and demonstrated the cutting-edge science available at the NWU.,” concluded Prof Mphahlele.

More about Prof Gidelew

Prof Amare Abebe Gidelew obtained his BSc physics degree with distinction in 2006 from the Addis Ababa University. He obtained his MSc (2009) and PhD (2013) from the University of Cape Town, specialising in theoretical cosmology.

After completing his studies, he joined the Physics subject group at the NWU’s Mahikeng Campus as a postdoctoral research fellow in 2014, under the mentorship of Prof Thebe Medupe. He was then appointed as a senior lecturer in 2015, and has since moved up the academic ladder to associate professor and now full professor.

He joined the Centre for Space Research as a researcher in 2017, and has since been actively participating in the centre’s research and postgraduate supervision activities.

He is a regular peer reviewer in many high-standing international journals such as Scientific Reports, European Physical Journal C, Physical Review D, Classical and Quantum Gravity, the International Journal of Geometric Methods in Modern Physics, the Canadian Journal of Physics, Physica Scripta, and Fortschritte der Physik.

Prof Gidelew is a Y-rated researcher with the National Research Foundation and is a member of the South African Institute of Physics, the African Astronomical Society, the International Astronomical Union, and the South African Mathematical Society. He is an affiliated researcher at the National Institute for Theoretical and Computational Sciences and the Centre of Excellence for Mathematical and Statistical Sciences, and a 2018 fellow of the Japan Society for the Promotion of Science.



Prof Amare Abebe Gidelew (left) receives his inauguration certificate form Prof Jeffrey Mphahlele, deputy vice-chancellor for research and innovation.

Submitted on Thu, 07/21/2022 - 09:30