Sathamangalam Ranga Iyengar Srinivasa Varadhan is an Indian American mathematician who is known for his fundamental contributions to probability theory and in particular for creating a unified theory of large deviations. Varadhan was born on 2 January 1940 in Chennai, India. Varadhan received a bachelor’s degree (1959) and master’s degree (1960) from the University of Madras before earning a doctorate (1963) from the Indian Statistical Institute in Calcutta. Varadhan's awards and honours include the National Medal of Science (2010) from President Barack Obama, "the highest honor bestowed by the United States government on scientists, engineers and inventors".