Robert Mortimer Ellis (1926–2013) was an American mathematician, specializing in topological dynamics.
[2] Ellis grew up in Philadelphia, served briefly in the U.S. Army, and then studied at the University of Pennsylvania, where he received his Ph.D. in 1953.
[2] He developed an algebraic approach to topological dynamics, leading to a strengthening with an alternate proof of the Furstenberg structure theorem.
In the year of his retirement, a conference was held in his honor at the University of Minnesota on April 5 and 6 1995; the conference proceedings were published in 1998 by the American Mathematical Society (AMS).
Upon his death he was survived by a grandchild, a daughter, and his son David, a professor of mathematics at Beloit College and a long-time collaborator with his father.