Indian-born Srinivasa SR Varadhan on Tuesday accepted the Norwegian Abel Prize, known as the 'Nobel Prize for mathematics'.
King Harald presented the award worth 6 million kroner ($920,000) at a ceremony in Oslo.
Before the ceremony, Varadhan met King Harald and Queen Sonja at the
Varadhan was cited for his, "fundamental contributions to probability theory and in particular for a unified theory of large deviations", the jury said.
In mathematics, probability theory is the tool used to analyse situations governed by chance, while his theory of large deviations was said to have provided explanations applicable in 'fields as diverse as quantum field theory, statistical physics, population dynamics, econometrics and finance, and traffic engineering'.
Varadhan, born 1940 in Chennai, has since 1963 worked at the Courant Institute of Mathematical Sciences, New York, where he is professor of mathematics and currently Frank J Gould Professor of Science. He is now a US citizen.
The Abel Prize was created in 2002 to commemorate the 200th centenary of the birth of Niels Henrik Abel. The Norwegian is acknowledged as one of the great names in mathematics although he died aged 26 only.
Last year, Swedish mathematician Lennart Carleson won the award. Hungarian-born Peter D Lax, professor of mathematics at New York University, was the 2005 winner.
Both Carleson and Lax were later on Tuesday slated to attend a banquet in honour of Varadhan.