STONY BROOK, N.Y. — Robert J. Aumann, a long-time member of the faculty at Stony Brook University and now a Visiting Leading Professor, was awarded the Nobel Prize in Economics for his work in game theory. Aumann shared the prize with another game theorist, Thomas C. Schelling of the University of Maryland. Aumann, 75, an Israel-American who now teaches at the Hebrew University in Jerusalem, had been a part-time faculty member from 1986 until 2003. His current work as a Visiting Professor is related to Stony Brook's Center for Game Theory.

Game theory is a branch of applied mathematics which uses models to study interactions between countries, businesses, or people. Devised in 1944, it is frequently used to explain conflict between nations and the dynamics of labor negotiations. In making the announcement in Stockholm, the Royal Swedish Academy of Sciences cited Aumann's work in identifying what outcomes can be upheld over time in long-run relations. He and Schelling will share the $1.3 million prize.

Aumann is a founding member of Stony Brook's Center for Game Theory, which has conducted conferences at the University for the last 16 years, drawing leading economists from around the world. He was the first to explain the concept of perfect competition with rigorous mathematics. Together with colleague Lloyd Shapley, he developed a theory of cooperative interactions among large groups of participants, which has numerous applications including cost allocations in complex systems.

Aumann was also the first to introduce the concept of “common knowledge” into economics and to show its effects on the strategic behavior of people. In addition, he invented and developed the theory of repeated games with incomplete information, in which the evolution of subtle relationships between the players over time could be analyzed. This shed light on how reputations are formed and demonstrated how cooperative behavior could emerge.

“We congratulate Professor Aumann on this extraordinary achievement,” said Stony Brook President Shirley Strum Kenny.“ He should be proud, and we are proud of him.”

The award marked the second Nobel Prize for a Stony Brook faculty member in three years. In 2003, Paul C. Lauterbur received the Nobel Prize for Medicine for his pioneering research that led to the development of the MRI while a Stony Brook Chemistry professor in the 1970s.