**Decorated Mathematician and Probabilist**

**New York City, New York**

Born in Madras (Tamil Nadu) in 1940, Srinivasa “Raghu” Varadhan’s importance to mathematics cannot be exaggerated. Varadhan’s interest in Mathematics was cultivated by one of his high school teachers. As a student, he would go to his teacher’s home to solve extra problems. Varadhan came to see these as ‘intellectual games’, like playing chess or solving puzzles. Varadhan’s father was a science teacher, who often supported and encouraged him. After graduating high school in 1955, Varadhan studied statistics for his bachelor’s degree from Presidency College at the University of Madras. Upon completion of his degree, he continued for a fifth year to get his master’s degree.

Varadhan, then, went onto the prestigious Indian Statistical Institute (ISI), which was deeply influential in his conceptual cultivation. He was convinced by legendary mathematicians and probabilists like R. Ranga Rao, K. R. Parthasarathy, and Veeravalli S. Varadarajan to alter his approach and focus more on mathematics than *just* statistics. The “famous four”, as they have come to be known in academic circles, solved one of the toughest probability distribution problems. At the ISI, he also received his doctorate under the guidance of the renowned statistician C. R. Ra0. Andrey Kolmogorov, perhaps the most significant mathematicians from the 20th century, was appointed as one of the examiners of Varadhan’s thesis. He took the thesis back with him to Moscow. And according to his report, the thesis was “*not the work of a student, but of a mature master*”.

Varadhan had earned quite a reputation. Such high praise was being noticed all over the world, in fact. The Courant Institute of the Mathematical Sciences at New York University (NYU) offered him a post-doctoral visitor position, which he held for three years (1963-66). Within six short years, Varadhan became a full professor at NYU (1972), after serving as assistant professor (1965) and associate professor (1968).

The research Varadhan has undertaken whilst at NYU has been revolutionary to say the least. Some of his early awards include the Birkhoff Prize (1994) and the Margaret and Herman Sokol Award of the Faculty of Arts and Sciences at NYU (1995). Varadhan and Daniel Stroock collaborated on four papers. They introduced new concepts that enabled them to prove or refute various mathematical theories in various process of diffusion processes. These publications earned the pair the prestigious Leroy P. Steele Prize from the American Mathematical Society (1996). Varadhan and Monroe D. Donsker were awarded the highly coveted Abel Prize for their contributions to ‘probability theory and for creating a unified theory of large deviation’ (2007). In addition to these, The Government of India also recognized Varadhan’s achievements and awarded him, the third-highest civilian award, the Padma Bhushan (2008). President Obama awarded him the National Medal of Science (2010), the highest honor conferred by the United States government on scientists, inventors and engineers. The Université Pierre et Marie Curie in Paris (2003) and the Indian Statistical Institute in Kolkata (2004) awarded him honorary degrees for his achievements to field of mathematics and probability.

His expertise and proficiency are valuable assets, not just to the field of mathematics, but to science overall. As such, he is a member of several noteworthy institutions. Some of these include the Third World Academy of Sciences (1988); the Institute of Mathematical Statistics (1991); the US National Academy of Sciences (1995); the Royal Society (1998); the Indian Academy of Sciences (2004); the Norwegian Academy of Science and Letters and the Society of Industrial and Applied Mathematics (both since 2009); and the American Mathematical Society (2012).

Some 50 years on, he still continues to teach at New York University at the Courant Institute, tackling even more advance levels of diffusion processes and improving his work on large deviations. Daniel Stroock was once quoted as saying, “*what distinguished Varadhan from nearly all the other gifted people is the remarkable command he exercises over his own gift. Varadhan can tolerate being wrong, at least occasionally. In addition, he is not one of the many mathematical princes who espouse the notion that all their obligations to humanity can be met through their contributions to mathematical research*”. From my readings and research, this is excerpt does Varadhan true justice. A humble genius, always willing to improve. Always willing to accept his limitations. Varadhan’s mind looks for solutions to questions we don’t even know exist, let alone ask. He has devoted his life to accurately measuring entities, units, possibilities, dispersion, etc. Ironically, his own love for mathematics, is the only thing, I’m sure, even he can’t measure.

**References**

“Srinivasa S. R. Varadhan.” *Abel Prize*. N.p., n.d. Web. 23 Jan. 2016.

O’Connor, J J, and E F Robertson. “Sathamangalam Ranga Iyengar Srinivasa Varadhan.”*Varadhan Biography*. University of St. Andrews, Feb. 2010. Web. 25 Jan. 2016.

“Interview with Srinivasa Varadhan.” Interview by R. Sujatha. *Asia Pacific Math News*. N.p., 10 Jan. 2012. Web. 21 Feb. 2016.

Gray, Jeremy John. “S.R. Srinivasa Varadhan.” *Encyclopædia Britannica*. Encyclopædia Britannica, Inc., n.d. Web. 21 Feb. 2016.

“Jury Chairs 2015.” *Infosys Science Foundation – Jury Chairs 2015*. N.p., n.d. Web. 20 Feb. 2016.

“S. R. Srinivasa Varadhan.” *Wikipedia*. Wikimedia Foundation, n.d. Web. 25 Jan. 2016.