Who Is Robert J. Aumann? What Is He Known for?

Robert J. Aumann is an Israeli mathematician who is known not only for his long white beard but also for his contributions to the realm of game theory. This is one area of mathematics used in competitive gameplay that analyzes strategies where the end result depends on the actions and reactions of other players. Aumann's work in this field led to him receiving the Nobel Prize in Economic Sciences in 2005 with his co-recipient, Thomas C. Schelling.

Early Life and Education

Robert J. Aumann was born in Germany in 1930. In 1938, his family fled to the U.S. to escape the Nazis during World War II. The family settled in New York where Aumann and his siblings completed their high school education.

Aumann attended the City College of New York, where he earned his undergraduate degree in science in 1950. He later attended the Massachusetts Institute of Technology (MIT) and graduated with his doctorate in 1955. His work focused on the mathematical theory of rope knots. He completed his post-doctoral work with the Analytical Research Group at Princeton. His work focused on the theoretical problem of defending a city from aerial attack. At that time he began to focus on game theory, a tool he had encountered through the mathematician John F. Nash, Jr. while at MIT.

In 1956, Aumann left the United States with his family and moved to Israel where he still resides. He took a position as an instructor of mathematics at the Hebrew University of Jerusalem. He is a faculty member at the university's Einstein Institute of Mathematics.

Notable Accomplishments

Robert J. Aumann's most noted contributions lie in the field of game theory.?But he first grabbed the attention of the mathematics world with his work on repeated games, which he published as a set of theories in 1959. He later developed and published his Folk Theorem. Taken together, these publications describe the relationship between equilibrium behavior in repeated games and cooperative behavior, the basis for the concept of correlated equilibrium.

Aumann was the first person to articulate correlated equilibrium as a phenomenon. Correlated equilibrium is similar to Nash's Equilibrium, though considered more flexible. In a correlated equilibrium, the players in a game choose based on some piece of public information available to each player and assume that the other players will not deviate from their best strategy given the same information. A repeated game where each player knows the past choices of the other players can converge to a correlated equilibrium.

Aumann explored the theory of games with incomplete information in collaboration with Michael Maschler. This involves games where the players do not have the same information, and the information they have may be dependent or independent of the other players' choices and information. Aumann's work in this area would go on to help shape the U.S. arms control negotiation strategy during the Cold War.

Honors and Awards

Aumann's shared the Nobel Prize in Economic Sciences in 2005 with economist and mathematician Thomas C. Schelling. The two won the prestigious award because their work enhanced the "understanding of conflict and cooperation through game-theory analysis.”

In addition to the Nobel Prize, Aumann was awarded a number of honorary degrees from schools like the University of Chicago.

Legacy

Aumann is a religious Jew and gained attention outside of the fields of math and economics for using game theory to analyze dilemmas in the Talmud or the Jewish scripture. He also briefly stirred controversy for his interest in biblical or Torah codes. However, after delving into some experimentation and research with peers, Aumann determined that the experiment failed to confirm the existence of any definitive code.

Aumann has given lectures within Israel on the importance of maintaining religious belief in order to keep the state alive. He has long been a vocal proponent of Israel as a Jewish state and cited game theory as he argued against the Israeli withdrawal from Gaza in 2005.

Personal Life

Aumann married Esther Schlesinger in April 1955. The two had five children together: Shlomo, Tamar, Yehonatan, Miriam, and Noga Judith. His son Shlomo was killed during the 1982 war in Lebanon when the tank he was in with another soldier was hit by opposing forces. A nonprofit organization was set up in Shlomo's name the year after his death. Aumann's wife died in Jerusalem in 1998 at the age of 67.

The Bottom Line

Robert J. Aumann is as well known for his long, white beard as he is for his work in mathematics. Aumann studied at MIT and Princeton, developing his work in game theory. His collaboration with Thomas C. Shelling in this field earned him the Nobel Prize in Economic Sciences in 2005. He now resides in Israel, where he is a faculty member of the Hebrew University of Jerusalem's Einstein Institute of Mathematics.