QuickTime™ and a decompressor are needed to see this picture. Intelligence Seminar Joseph Halpern Professor Computer Science Department Cornell University Beyond Nash Equilibrium: Solution Concepts for the 21st Century Nash equilibrium is the most commonly used notion of equilibrium in game theory. However, it suffers from numerous problems. Some are well known in the game theory community. For example, the Nash equilibrium of repeated prisoner's dilemma is neither normatively nor descriptively reasonable. However, new problems arise when considering Nash equilibrium from a computer science perspective. For example, Nash equilibrium is not robust (it does not tolerate "faulty" or "unexpected" behavior), it does not deal with coalitions, it does not take computation cost into account, and it does not deal with cases where players are not aware of all aspects of the game. In this talk, I discuss solution concepts that try to address these shortcomings of Nash equilibrium. This talk represents joint work with various collaborators, including Ittai Abraham, Danny Dolev, Rica Gonen, Rafael Pass, and Leandro Rego. No background in game theory will be presumed. BIO: JOSEPH HALPERN received a B.Sc. in mathematics from the University of Toronto in 1975 and a Ph.D. in mathematics from Harvard in 1981. In between, he spent two years as the head of the Mathematics Department at Bawku Secondary School, in Ghana. After a year as a visiting scientist at MIT, he joined the IBM Almaden Research Center in 1982, where he remained until 1996, also serving as a consulting professor at Stanford. In 1996, he joined the CS Department at Cornell, and is now the department chair. Halpern's major research interests are in reasoning about knowledge and uncertainty, security, distributed computation, decision theory, and game theory. Together with his former student, Yoram Moses, he pioneered the approach of applying reasoning about knowledge to analyzing distributed protocols and multi-agent systems. He has coauthored six patents, two books ("Reasoning About Knowledge" and "Reasoning about Uncertainty"), and over 300 technical publications. Halpern is a Fellow of AAAI, AAAS, ACM, IEEE, and SEAT (Society for the Advancement of Economic Theory). Among other awards, he received the ACM SIGART Autonomous Agents Research Award in 2011, the Dijkstra Prize in 2009, the ACM/AAAI Newell Award in 2008, the Godel Prize in 1997, was a Guggenheim Fellow in 2001-2002, and a Fulbright Fellow in 2001-2002 and 2009-2010. Two of his papers have won best-paper prizes at IJCAI (1985 and 1991), and another two received best-paper awards at the Knowledge Representation and Reasoning Conference (2006 and 2012). He was the editor-in-chief of the Journal of the ACM (1997-2003) and has been the program chair of a number of conferences, including the Symposium on Theory in Computing (STOC), Logic in Computer Science (LICS), Uncertainty n AI (UAI), Principles of Distributed Computing (PODC), and Theoretical Aspects of Rationality and Knowledge (TARK). INTELLIGENCE SEMINAR Tuesday • 17 September 2013 Gates&Hillman 6501 • 12:00 PM Faculty Host: Ariel Procaccia Appointments: [email protected].