S. R. S. Varadhan is an Indian-American mathematician known for his significant contributions to the field of probability theory and stochastic processes. He was born on January 2, 1940, in Chennai, India, and later moved to the United States for his academic career. Varadhan is particularly recognized for his work on large deviations, which helps in understanding the behavior of random processes. In 2007, Varadhan was awarded the prestigious National Medal of Science for his outstanding achievements in mathematics. He has also received the Shaw Prize in Mathematical Sciences in 2010. Varadhan's research has had a profound impact on various fields, including statistical mechanics and information theory.