Srinivasa Ramanujan: Going Strong at 125

Srinivasa Ramanujan is one of the greatest mathematicians in history and one of the most romantic figures in the mathematical world as well. Born on December 22, 1887, to a poor Hindu Brahmin family in Erode in the state of Tamil Nadu in South India, Ramanujan was a self-taught genius who discovered a variety of bewildering identities starting from his school days. There is a legend that the Hindu goddess Namagiri in the neighbouring town of Namakkal used to come in his dreams and give him these formulae. Unable to find individuals in India to understand and evaluate his findings, Ramanujan wrote two letters in 1913 to G. H. Hardy of Cambridge University, England, listing several of his most appealing formulae. The depth and startling beauty of these identities convinced Hardy that Ramanujan was on a par with Euler and Jacobi in sheer manipulative ability. At Hardy’s invitation, Ramanujan went to Cambridge in 1914. The rest is history. In the five years he was in England, Ramanujan published several important papers, some of which stemmed from his discoveries in India; he collaborated with G. H. Hardy and wrote two very influential papers with him. For his path-breaking contributions, Ramanujan was honoured by being elected Fellow of Trinity College, Cambridge, and Fellow of the Royal Society (FRS) even though he did not have a college degree! The rigours of life in England during the First World War, combined with his own peculiar habits, led to a rapid decline in his health. Ramanujan returned to Madras, India, in 1919 a very sick man and died shortly after on April 26, 1920. Even during his last days, his mathematical creativity remained undiminished. He wrote one last letter to Hardy in January 1920 outlining his discovery of the mock theta functions, considered to be among his deepest contributions. In the decades after Ramanujan’s death, we have come to realise the depth, breadth, and significance of his many discoveries. Ramanujan’s work has had a major influence on several branches of mathematics, most notably in number theory and classical analysis, and even in some areas of physics.