Robert Mortimer Ellis (1926–2013) was an American mathematician, specializing in

topological dynamics In mathematics, topological dynamics is a branch of the theory of dynamical systems in which qualitative, asymptotic properties of dynamical systems are studied from the viewpoint of general topology. Scope The central object of study in topolo ...

. Ellis grew up in Philadelphia, served briefly in the U.S. Army, and then studied at the

University of Pennsylvania The University of Pennsylvania (also known as Penn or UPenn) is a private research university in Philadelphia. It is the fourth-oldest institution of higher education in the United States and is ranked among the highest-regarded universit ...

, where he received his Ph.D. in 1953. He was a postdoc at the

University of Chicago The University of Chicago (UChicago, Chicago, U of C, or UChi) is a private university, private research university in Chicago, Illinois. Its main campus is located in Chicago's Hyde Park, Chicago, Hyde Park neighborhood. The University of Chic ...

from 1953 to 1955. He was at

Pennsylvania State University The Pennsylvania State University (Penn State or PSU) is a public state-related land-grant research university with campuses and facilities throughout Pennsylvania. Founded in 1855 as the Farmers' High School of Pennsylvania, Penn State becam ...

from 1955 to 1957 an assistant professor and from 1957 to 1963 an associate professor and at

Wesleyan University Wesleyan University ( ) is a private liberal arts university in Middletown, Connecticut. Founded in 1831 as a men's college under the auspices of the Methodist Episcopal Church and with the support of prominent residents of Middletown, the c ...

from 1963 to 1967 a full professor. At the

University of Minnesota The University of Minnesota, formally the University of Minnesota, Twin Cities, (UMN Twin Cities, the U of M, or Minnesota) is a public university, public Land-grant university, land-grant research university in the Minneapolis–Saint Paul, Tw ...

he was a full professor from 1967 to 1995, when he retired as professor emeritus. He developed an algebraic approach to topological dynamics, leading to a strengthening with an alternate proof of the Furstenberg structure theorem. He was the author or coauthor of about 40 research publications. 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).Ellis, Robert, Mahesh G. Nerurkar, Douglas Dokken, and David Ellis
Topological Dynamics and Applications: A Volume in Honor of Robert Ellis: Proceedings of a Conference in Honor of the Retirement of Robert Ellis, April 5–6, 1995, University of Minnesota
Vol. 215. American Mathematical Soc., 1998. He was elected a Fellow of the AMS in 2012. Ellis was predeceased by his wife. Upon his death he was survived by a grandchild, a daughter, and his son David, a professor of mathematics at

Beloit College Beloit College is a private liberal arts college in Beloit, Wisconsin. Founded in 1846, when Wisconsin was still a territory, it is the state's oldest continuously operated college. It is a member of the Associated Colleges of the Midwest and ...

and a long-time collaborator with his father.

References

{{DEFAULTSORT:Ellis, Robert Mortimer 1926 births 2013 deaths 20th-century American mathematicians 21st-century American mathematicians University of Pennsylvania School of Arts and Sciences alumni Pennsylvania State University faculty University of Minnesota faculty Fellows of the American Mathematical Society