Thomas Milton Liggett

University of California, Los Angeles, Los Angeles, California ~Professor Emeritus of Mathematics. Major figure in the field of interacting particle systems, an important and active part of probability theory that has applications in many areas, including statistical physics, biology, the theory of epidemics, ecology, and traffic flow analysis. Began work in this area in 1972 with the rigorous construction of these systems, and has continued with analysis of the longtime behavior of the major models, including contact and exclusion processes. Author of two major books on the subject, Interacting Particle Systems (1985) and Stochastic Interacting Systems: Contact, Voter and Exclusion Processes (1999). Constructed semigroups of nonlinear transformations (1971) as well as the proof of the currently best form of the subadditive ergodic theorem (1985). Developed a general negative correlations theory, with applications to the exclusion process (2009), as well as the proof of the long-standing Aldous spectral gap conjecture (2010). Named both a Sloan and Guggenheim Fellow and a Wald Memorial Lecturer of the Institute of Mathematical Statistics. Invited speaker at the International Congress of Mathematicians.~