‘Gravitational waves, ripples in the fabric of space-time produced by colossal cosmic events, have been a focal point of scientific inquiry for decades. The groundbreaking detection of these waves in 2015 by the LIGO-Virgo collaboration marked a monumental achievement confirming Einstein’s predictions. Despite this, the behaviour of gravitational waves has predominantly been understood through classical physics, much like our everyday comprehension of natural phenomena. The intriguing question at the heart of the research is whether these waves might also possess a quantum dimension.’ Thus Dr Partha Nandi talks about the topic of an important article which he co-authored with Dr Bibhas Ranjan Majhi about their work on gravitational waves. It appeared in Physics Letters B.
Dr Nandi continues his introduction to their research: ‘Just as Einstein’s quantisation of light in 1905 provided indirect evidence of photons through the photoelectric effect — leading to the development of quantum theory — this study aims to uncover similar indirect evidence for the quantum nature of gravitational waves. By investigating the possibility that these waves could be associated with hypothetical quantum particles known as gravitons, the research seeks to bridge the gap between classical and quantum descriptions of gravity, offering fresh insights into the fundamental nature of the universe.’
Background and journey
He also talks about what brought him to the current place in his academic and career story: ‘I come from a humble background and completed my PhD in theoretical high-energy physics at the SN Bose National Centre for Basic Sciences (SNBNCBS) in India in 2021, focusing on quantum gravity phenomenology. I was then awarded a one-year visiting researcher position at the Department of Astrophysics and High Energy Physics at SNBNCBS, where I pursued research in gravitational wave astronomy. During this period, I also contributed as a guest faculty member in postgraduate programmes at colleges affiliated with Calcutta University and the Ramakrishna Mission Vivekananda Research Institute.’
He continues: ‘My academic journey then advanced to a postdoctoral position at Stellenbosch University in 2023. I am currently a postdoctoral fellow at NITheCS, where I explore the quantum aspects of gravitational waves and Modified Newtonian Dynamics (MOND) using quantum geometric frameworks. This research aims to deepen our understanding of spacetime and gravitational phenomena.’
He acknowledges the influence of people close to him in his work: ‘My achievements are primarily due to the unwavering support of my mother, whose sacrifices created a nurturing environment that enabled me to overcome many challenges. I am also deeply grateful to my teachers, supervisors, collaborators and project students, as well as my current mentor, Prof Frederik Scholtz (Stellenbosch University), as well as Prof Francesco Petruccione and Ms René Kotzé at NITheCS. Their invaluable support has played a crucial role in advancing my research efforts in South Africa.’
Applications of the research
Dr Nandi believes their predictions do not only enhance our understanding of the universe, ‘but also establish a critical foundation for advancing future quantum technologies, especially in relation to the upcoming LIGO-India project (INDIGO).’ Furthermore, he believes that ‘the efforts of South African research institutions such as NITheCS and the Centre for Gravitational Astrophysics at Stellenbosch University, are further strengthened by our findings. These institutions contribute to gravitational wave research through data analysis, collaborations and theoretical developments, underscoring the collaborative nature of our research community and its importance in the global scientific landscape.’