Rick Durrett

Richard Timothy Durrett (born 1951) is an American mathematician whose research concerns probability theory, stochastic processes, and their applications to mathematical biology, including population genetics, ecology, epidemiology, and cancer modeling. He is the James B. Duke Emeritus Professor of Mathematics at Duke University, having previously held faculty positions at the University of California, Los Angeles (UCLA) and Cornell University.

Durrett was elected to the United States National Academy of Sciences in 2007 and to the American Academy of Arts and Sciences in 2002. He is also a fellow of the American Mathematical Society, the Institute of Mathematical Statistics, and the American Association for the Advancement of Science. His textbook Probability: Theory and Examples was described in a review for the Mathematical Association of America as one of the two most popular graduate-level texts on probability, alongside Billingsley's Probability and Measure.

Education

Durrett received his Bachelor of Science (1972) and Master of Science (1973) degrees in mathematics from Emory University. He then entered the Operations Research program at Stanford University, where he completed his Ph.D. in 1976 under the supervision of Donald Iglehart. His doctoral dissertation, titled Conditioned Limit Theorems for Some Null Recurrent Markov Processes, appeared in the Annals of Probability in 1976.

Durrett has said that he initially enrolled at Emory as a pre-medical student during the Vietnam War era but switched to mathematics after finding the laboratory component of pre-med unappealing, while still wanting to apply mathematics to real-world problems; this led him to operations research at Stanford. In 1985 he joined the faculty of Cornell University, where he remained for 25 years.

Research

Durrett's research spans probability theory and its applications. His early work focused on interacting particle systems, percolation theory, and contact processes, building on the frameworks developed by Thomas M. Liggett and Frank Spitzer. His 1980 paper with T. M. Liggett determined the shape of the limit set in Richardson's model for the spread of an infection.

Stochastic spatial models in ecology

In the late 1980s Durrett began a long-running collaboration with the ecologist Simon Levin of Princeton University on stochastic spatial models in ecology. Their subsequent papers studied species–area curves, allelopathy, interspecific competition, and the spread of epidemics using interacting particle systems and stochastic spatial models.

Population genetics and cancer

Beginning in the late 1990s Durrett turned to population genetics, working with C. F. Aquadro and others on the evolutionary dynamics of microsatellite repeat length distributions and, with Jason Schweinsberg, on approximating selective sweeps by random partitions. His 2008 paper with Deena Schmidt, Waiting for two mutations, studied the limits of Darwinian evolution in regulatory sequence evolution.

Durrett's later research has applied branching processes and stochastic models to cancer biology, including models of tumor heterogeneity, the evolution of resistance to therapy, and the dynamics of clonal expansion.

Random graphs

A third strand of Durrett's work concerns stochastic processes on random graphs. He showed, with Shirshendu Chatterjee, that contact processes on random graphs with power-law degree distributions have critical value zero—meaning infection can survive for any positive infection rate. His 2010 Inaugural Article as a member of the National Academy of Sciences, published in the Proceedings of the National Academy of Sciences, examined the spread of epidemics and opinions on random graphs. This work is collected in part in his monograph Random Graph Dynamics (Cambridge University Press, 2007; second edition Springer, 2025).

Honors and awards

Durrett has received a number of honors recognizing his contributions to probability theory and mathematical biology. He was awarded a Sloan Research Fellowship from the Alfred P. Sloan Memorial Foundation for 1981–1983, and an AMS Centennial Fellowship for 1984–1986. He was elected a fellow of the American Association for the Advancement of Science in 2009

Selected publications

Books

Selected research papers