In Memoriam: Prof. Santosh Kumar, An Example of Brilliance, Passion, and Humility
The recent and untimely passing of Professor Santosh Kumar, Associate Professor at the School of Natural Sciences, Shiv Nadar Institution of Eminence (SNIoE), represents the loss of a truly exceptional physicist, a beloved mentor, and a remarkable human being.
Prof. Kumar’s academic journey began in modest circumstances in Hazaribagh, Jharkhand, where he completed his B.Sc. in Physics with honors at Vinoba Bhave University in 2002. He then moved to Delhi to pursue a Master’s degree in Physics at Jawaharlal Nehru University (JNU), one of the most prestigious institutions both in India and globally. This was a major transition for him and posed great challenges in multiple ways. First, very few people spoke English in his hometown, as Western media and social media platforms had much less presence in rural and suburban India at that time. Second, moving to a sophisticated, culturally progressive city like Delhi to study at a highly prestigious university like JNU was most certainly difficult not only academically, but also socially.
Despite these hurdles, Prof. Kumar graduated as a gold medalist in his class in 2007. Afterwards, he pursued his Ph.D. under Prof. Akhilesh Pandey, who was already a leading expert in Random Matrix Theory (RMT). His research with Prof. Pandey not only earned him recognition in this highly mathematical area within physics, but also allowed him to forge connections with global leaders in the field.
Following his doctoral studies, Prof. Kumar expanded his research horizons at the University of Duisburg–Essen from 2011 to 2013, where he delved into time series analysis and quantum chaos through postdoctoral studies under Prof. Thomas Guhr. During this time, Prof. Kumar explored the application of RMT to these complex areas. In 2013, Prof. Kumar joined SNIoE as an Assistant Professor—he was later promoted to Associate Professor in 2019.
Contributions to Science: Bridging theory and application
Prof. Kumar’s scientific contributions to the field of mathematics and physics are extensive. His collaborations with Prof. Peter Forrester led to one of his most noteworthy achievements. In his paper titled “Exact evaluations of some Meijer G-functions and probability of all eigenvalues real for product of two Gaussian matrices” (Journal of Physics A, 2015), Prof. Kumar leveraged the recursive properties of the somewhat obscure Meijer G-functions to prove a conjecture Prof. Forrester had proposed previously. More specifically, this conjecture addressed the arithmetic and structural properties of the probability that all eigenvalues are real for a product of two real Gaussian matrices. The importance of this work was recognised by the journal, which highlighted it via an interview.
Prof. Kumar published numerous papers across various physics and mathematical journals, often tiptoeing at the crossroads between purely theoretical and application-inclined research. His studies extended into bi-orthogonal invariant ensembles, structured random matrices, and marginal eigenvalue distributions, culminating in publications in prestigious journals such as Journal of Physics A, Physica D, and The Ramanujan Journal. He also explored topics such as spectral density and von Neumann entropy in random pure states (Journal of Physics A, 2011), and the distribution of scattering matrix elements in quantum chaotic systems (Physical Review Letters, 2013).
Without a doubt, Prof. Kumar had a remarkable ability to seamlessly connect abstract theoretical constructs with applied problems in quantum information, telecommunications, and complex networks. As shared by one of his students, “It is extraordinarily rare to encounter a theoretical physicist with his depth of enthusiasm for electronics, experimental physics, and engineering sciences. Though fundamentally a mathematician and theoretical physicist, his expertise reached into many other areas, encompassing semiconductor and materials physics, as well as electrical and communication engineering.”
During his tenure at SNIoE, Prof. Kumar earned numerous accolades, including a certificate of appreciation from the organising committee of a five-day national workshop jointly conducted by the Indian Mathematics Consortium and the Dayalbagh Educational Institute. He also received the Opportunities for Undergraduate Research (OUR) Supervision Award and the Outstanding Research Award, both from SNIoE. Reflecting on his enduring contributions, Prof. Susanta Roy, HoD of Physics at SNIoE, adds: “Santosh’s work will resonate through time. His contributions to theoretical and applied physics have not only advanced our understanding but also brought a unique depth to the community here at SNIoE. His mentorship and friendship will be missed, but his impact will never be forgotten.”
A Beloved Mentor Who Shaped Lives
Prof. Kumar was not only highly regarded as an outstanding academic, but also as an exemplary human being. At SNIoE, he focused on building a collaborative group environment, where members could work together harmoniously and free from rivalry. Often noted as a witty person of few words, Prof. Kumar always carried himself with dignity and calm. Notably, he always showed great respect for his Ph.D. students and was very understanding of their personal and professional challenges; perhaps he saw in them a reflection of his younger self and the struggles he had faced. “Santosh Sir was exceptionally brilliant, a true genius. Yet, he was the most unassuming genius I’ve ever met, incredibly grounded, down-to-earth, and extremely hard-working,” shares another of his students, remembering him fondly.
Dr. Santosh excelled at managing administrative responsibilities, consistently rising to the occasion, no matter how challenging the task. He also made significant contributions to the department's outreach efforts, embodying a spirit of service and dedication. Reflecting on his multifaceted contributions, Dr. Roy adds, “Santosh was a rare blend of intellect and kindness. His passion for physics was infectious, but even more inspiring was his empathy and unwavering support for everyone around him. He established an excellent collaboration with both theoretical and experimental physicists in the department, and leaves behind a legacy of brilliance and compassion that will guide us forever.”
We at SNIoE deeply mourn the passing of Professor Santosh Kumar. As a distinguished physicist, a devoted mentor, and an exceptional human being, he leaves behind an irreplaceable void. His presence will endure in the work he leaves behind and the countless lives he touched, remaining an integral part of our institution’s history.
Our thoughts are with his family, friends, and all who had the privilege of working alongside him.