Michael Shub | |
---|---|
Born | Michael Ira Shub August 17, 1943 |
Nationality | American |
Alma mater | University of California, Berkeley |
Known for | Blum Blum Shub pseudorandom number generator |
Scientific career | |
Fields | Mathematics |
Institutions | Brandeis University University of California, Santa Cruz Queens College at the City University of New York Thomas J. Watson Research Center University of Toronto University of Buenos Aires |
Michael Ira Shub (born August 17, 1943) is an American mathematician who has done research into dynamical systems and the complexity of real number algorithms.
In 1967, Shub obtained his Ph.D. degree at the University of California, Berkeley with a thesis entitled Endomorphisms of Compact Differentiable Manifolds. In his Ph.D. thesis, he introduced the notion of expanding maps, which gave the first examples of structurally stable strange attractors. His advisor was Stephen Smale. [1]
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. In 1974, he proposed the Entropy Conjecture, an open problem in dynamical systems, which was proved by Yosef Yomdin for mappings in 1987. [2]
From 1985 to 2004, he joined IBM's Thomas J. Watson Research Center. In 1987, 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. [3] [4] [5] In 1993, Shub and Stephen 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. [6]
From 1995 to 1997, Shub was the founding chair of the Society for the Foundations of Computational Mathematics. In 2001, Shub became a founding editor of their journal, Foundations of Computational Mathematics. [7]
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. [8]
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. [9]
From 2004 to 2010, he worked at the University of Toronto. [7] After 2010, he became a researcher at the University of Buenos Aires and at the Graduate Center of the City University of New York. [7] Since 2016, he has been Martin and Michele Cohen Professor and Chair of the Mathematics Department at City College of New York. [7]
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Lenore Carol Blum is an American computer scientist and mathematician who has made contributions to the theories of real number computation, cryptography, and pseudorandom number generation. She was a distinguished career professor of computer science at Carnegie Mellon University until 2019 and is currently a professor in residence at the University of California, Berkeley. She is also known for her efforts to increase diversity in mathematics and computer science.
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In computation theory, the Blum–Shub–Smale machine, or BSS machine, is a model of computation introduced by Lenore Blum, Michael Shub and Stephen Smale, intended to describe computations over the real numbers. Essentially, a BSS machine is a Random Access Machine with registers that can store arbitrary real numbers and that can compute rational functions over reals in a single time step. It is closely related to the Real RAM model.
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