An Indian American, Srinivasa SR Varadhan of the Courant Institute of Mathematical Sciences, New York, has won the 2007 Abel Prize awarded by the Norwegian Academy of Science and Letters.

The prize, which is worth $920,000, has been given for Varadhan's "fundamental contributions to probability theory and in particular for creating a unified theory of large deviation".

"Varadhan's work has great conceptual strength and ageless beauty. His ideas have been hugely influential and will continue to stimulate further research for a long time," the Abel Committee said.

Varadhan was born on January 2, 1940, in Chennai. He studied at Madras University and got a Ph D from the Indian Statistical Institute, Calcutta. The distinguished Indian statistician, C R Rao, was his thesis advisor.

During his thesis defence, Varadhan noticed a visitor in the room whom he did not know and who asked many penetrating questions. After the exam he discovered that it was the famous Russian mathematician and probabilist A N Kolmogorov.

Rao had arranged the date of the exam knowing that Kolmogorov would be visiting India then in order to present his star student before him and was not disappointed.