Michael Ira Shub (born August 17, 1943) is an
American mathematician who has done research into
dynamical systems
In mathematics, a dynamical system is a system in which a function describes the time dependence of a point in an ambient space. Examples include the mathematical models that describe the swinging of a clock pendulum, the flow of water in a p ...
and the complexity of
real number algorithms.
Biography
Shub obtained his
Ph.D. degree at the
University of California, Berkeley with a thesis entitled ''
Endomorphisms
In mathematics, an endomorphism is a morphism from a mathematical object to itself. An endomorphism that is also an isomorphism is an automorphism. For example, an endomorphism of a vector space is a linear map , and an endomorphism of a grou ...
of
Compact Differentiable Manifold
In mathematics, a differentiable manifold (also differential manifold) is a type of manifold that is locally similar enough to a vector space to allow one to apply calculus. Any manifold can be described by a collection of charts (atlas). One ma ...
s'' on 1967. His advisor was
Stephen Smale
Stephen Smale (born July 15, 1930) is an American mathematician, known for his research in topology, dynamical systems and mathematical economics. He was awarded the Fields Medal in 1966 and spent more than three decades on the mathematics facult ...
.
From 1967 to 1985 he worked at
Brandeis University, the
University of California, Santa Cruz and the
Queens College at the City University of New York
Queens College (QC) is a public college in the Queens borough of New York City. It is part of the City University of New York system. Its 80-acre campus is primarily located in Flushing, Queens. It has a student body representing more than 170 ...
. From 1985 to 2004 he joined
IBM's
Thomas J. Watson Research Center. From 2004 to 2010 he worked at the
University of Toronto. After 2010 he is a researcher at the
University of Buenos Aires and at the City University of New York.
Shub was the Chair of the
Society for the Foundations of Computational Mathematics from 1995 to 1997. In 2012, a conference, ''From Dynamics to Complexity'', was organised at the Fields Institute in
Toronto celebrating his work.
In 2015 he was elected as a
fellow of the
American Mathematical Society "for contributions to smooth dynamics and to complexity theory."
Since August 2016, he has been Martin and Michele Cohen Professor and Chair of the Mathematics Department at
City College of New York
The City College of the City University of New York (also known as the City College of New York, or simply City College or CCNY) is a public university within the City University of New York (CUNY) system in New York City. Founded in 1847, Cit ...
.
Work
Shub has produced publications in dynamical systems and in the complexity of real number algorithms. In his Ph.D. thesis in 1967, he introduced the notion of expanding maps, which gave the first examples of structurally stable strange attractors. In 1974 he proposed the Entropy Conjecture, an open problem in dynamical systems, which was proved by Yosef Yomdin for
mappings in 1987.
This same year, Shub published his book ''Global Stability of Dynamical Systems'', which is often used as a reference in introductory and advanced books on the subject of dynamical systems. Shub, along with coauthors Lenore and Manuel Blum, described a simple, unpredictable, secure
random number generator (see
Blum Blum Shub). This random generator is useful from theoretical and practical perspectives.
In 1989 he proposed with
Lenore Blum and Stephen Smale the notion of
Blum–Shub–Smale machine, an alternative to the classical Turing model of computation. Their model is used to analyse the computability of functions.
In 1993, Shub and Smale initiated a rigorous analysis of
homotopy-based algorithms for solving systems of nonlinear algebraic equations, which has inspired much of the work in that area during the last two decades.
Shub was one of the founders of the nonprofit association
Foundations of Computational Mathematics, and editor of their journal ''
Foundations of Computational Mathematics'' with the same name until 2009.
Selected publications
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References
External links
Personal websiteat the City College of New York.
{{DEFAULTSORT:Shub, Michael Ira
1943 births
Living people
20th-century American mathematicians
21st-century American mathematicians
University of California, Berkeley alumni
Fellows of the American Mathematical Society
Brandeis University faculty
City University of New York faculty
Graduate Center, CUNY faculty
City College of New York faculty
University of California, Santa Cruz faculty
University of Toronto faculty
University of Buenos Aires faculty
IBM Research computer scientists