The mysteries of gravity, cosmology and astrophysics have always been more than an academic interest for KwaZulu-Natal (UKZN) PhD graduate Dr Sumeekha Singh – indeed they are a lifelong fascination that have ultimately shaped her career.
Singh graduated with a PhD in Applied Mathematics for her thesis titled: ‘Dust and Pressure Universes in Higher Dimensional Einstein-Gauss-Bonnet Gravity’. She was supervised by Professor Sunil Maharaj and Dr Byron Brassel.
Her decision to pursue doctoral studies through UKZN was driven by the Institution’s unique standing in South Africa in the field of theoretical gravity and cosmology research.
“The University of KwaZulu-Natal is the only institution in South Africa that offers ongoing and current research for the theoretical study of gravity, cosmology and astrophysics,” said Singh. “I wanted to contribute to a niche field like Einstein-Gauss-Bonnet gravity.”
She said the Astrophysics Research Centre (ARC) at UKZN provided invaluable mentorship and support throughout her academic journey. “I’ve also had the pleasure of working with wonderful supervisors who are established researchers in the field,” she said.
Completing her doctorate at UKZN also had personal significance. “It is deeply meaningful to walk the same halls as my mother once did; completing my PhD here makes the achievement feel even sweeter,” she reflected.
Singh’s research investigated cosmological and astrophysical models in Einstein-Gauss-Bonnet gravity in higher dimensions. Exact solutions to the field equations were generated and the physical features were studied for a dark matter equation of state for dust distributions and pressure models.
“The dynamics of the model are governed by a nonlinear Abelian differential equation which was incredibly difficult to solve,” Singh explained. “The analysis had shown that radiating bodies have geometrical and physical features that are distinct from general relativity, offering a deeper understanding of how modified gravitational theories can influence large scale cosmological dynamics.”
Singh’s passion for the field stems from her fascination with both the microscopic and cosmic scales of existence.
“I have always been mesmerised by the mathematical beauty of the tiny quantum realm to the daunting scales of the universe and perpetually haunted by the unification of gravity and quantum mechanics, often dubbed as the theory of everything,” she said.
She described modified gravity and theoretical cosmology as tools for discovering innovative ways to refine gravitational models to match observed phenomena. “The quest for a theory of everything remains one of the most profound, unresolved challenges in modern physics,” Singh said. “I hope to inch us a little closer through the study of higher dimensional gravitational models such as Einstein-Gauss-Bonnet gravity which has its links to string theory.”
According to Singh, Einstein-Gauss-Bonnet gravity remains one of the most promising modified theories of gravity because it retains general relativity in low-energy conditions while extending into higher-dimensional and high-curvature regimes.
Her study examined dust-filled universes, pressure-dominated cosmological models and radiating stellar configurations within higher-dimensional Einstein-Gauss-Bonnet gravity. Together, these models demonstrated the versatility of the theory in addressing both cosmological and astrophysical phenomena while extending Einstein’s theory into higher dimensions.
Singh hopes to secure a postdoctoral fellowship to continue building her expertise in cosmology and astrophysics and also envisions an interdisciplinary future that extends beyond physics and mathematics.
“Over the course of my lifetime, I want to dabble in interdisciplinary research ranging from collaborations in marine biology to climatology to computer animation,” she said. “I would also like one day to obtain a Bachelor of Arts in fine art or political science. I want to be an effective curator and communicator of art and science.”
Singh credited much of her success to her late parents, both of whom profoundly shaped her academic and personal development.
“It was my mother who first put me on the track to studying astrophysics at UKZN in my undergrad years,” she said. “She supported me fiercely through my studies and always stressed the importance of getting an education.”
Her mother succumbed to cancer during Singh’s honours year, while her father had died when she was young. Despite these hardships, Singh said their influence remained central to who she had become.
“My father sparked my curiosity of the universe and harmony with nature at an early age,” she said. “I definitely would not be who or where I am today without the support and timeless guidance of my parents.”
Outside academia, Singh immerses herself in creative pursuits ranging from painting and crocheting to gaming and music. An avid artist, she uses her paintings to promote astronomy and raise awareness about social and environmental issues. She also enjoys attending rock and metal concerts, cosplaying at comic conventions and learning to play bass guitar.
Singh hopes her story will encourage others who struggle academically to persevere.
“I was not always good at mathematics, nor did it come naturally to me as a kid,” she said. “The change in my understanding and the eventual success later on came through focus, discipline and repetition.”
She added, “I firmly believe that being skilled in mathematics does not require you to be a genius. It just requires you to be insatiably curious.”
Words: Sally Frost
Photograph: Sethu Dlamini