James A. Yorke

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James Alan Yorke
James A Yorke.jpg
Born
James Alan Yorke

(1941-08-03) August 3, 1941 (age 81)
NationalityAmerican
Alma mater
Known for Kaplan–Yorke conjecture
Awards Japan Prize (2003)
Scientific career
Fields Math and Physics (theoretical)
Institutions University of Maryland, College Park
Doctoral students Tien-Yien Li

James A. Yorke (born August 3, 1941) is a Distinguished University Research Professor of Mathematics and Physics and former chair of the Mathematics Department at the University of Maryland, College Park.

Contents

Born in Plainfield, New Jersey, United States, Yorke attended The Pingry School, then located in Hillside, New Jersey. Yorke is now a Distinguished University Research Professor of Mathematics and Physics with the Institute for Physical Science and Technology at the University of Maryland. In June 2013, Dr. Yorke retired as chair of the University of Maryland's Math department. He devotes his university efforts to collaborative research in chaos theory and genomics.

He and Benoit Mandelbrot were the recipients of the 2003 Japan Prize in Science and Technology: Yorke was selected for his work in chaotic systems. In 2003 He was elected a Fellow of the American Physical Society. [1] and in 2012 became a fellow of the American Mathematical Society. [2]

He received the Doctor Honoris Causa degree from the Universidad Rey Juan Carlos, Madrid, Spain, in January 2014. [3] In June 2014, he received the Doctor Honoris Causa degree from Le Havre University, Le Havre, France. [4] He received the Thomson Reuters Citations Laureate in Physics 2016. [5]

Contributions

Period three implies chaos

He and his co-author T.Y. Li coined the mathematical term chaos in a paper they published in 1975 entitled Period three implies chaos, [6] in which it was proved that any one-dimensional continuous map

F: RR

that has a period-3 orbit must have two properties:

(1) For each positive integer p, there is a point in R that returns to where it started after p applications of the map and not before.

This means there are infinitely many periodic points (any of which may or may not be stable): different sets of points for each period p. This turned out to be a special case of Sharkovskii's theorem. [7]

The second property requires some definitions. A pair of points x and y is called “scrambled” if as the map is applied repeatedly to the pair, they get closer together and later move apart and then get closer together and move apart, etc., so that they get arbitrarily close together without staying close together. The analogy is to an egg being scrambled forever, or to typical pairs of atoms behaving in this way. A set S is called a scrambled set if every pair of distinct points in S is scrambled. Scrambling is a kind of mixing.

(2) There is an uncountably infinite set S that is scrambled.

A map satisfying Property 2 is sometimes called "chaotic in the sense of Li and Yorke". [8] [9] Property 2 is often stated succinctly as their article's title phrase "Period three implies chaos". The uncountable set of chaotic points may, however, be of measure zero (see for example the article Logistic map), in which case the map is said to have unobservable nonperiodicity [10] :p. 18 or unobservable chaos.

O.G.Y control method

He and his colleagues (Edward Ott and Celso Grebogi) had shown with a numerical example that one can convert a chaotic motion into a periodic one by a proper time-dependent perturbation of the parameter. This article is considered a classic among the works in the control theory of chaos, and their control method is known as the O.G.Y. method.

Books

Together with Kathleen T. Alligood and Tim D. Sauer, he was the author of the book Chaos: An Introduction to Dynamical Systems.

Related Research Articles

<span class="mw-page-title-main">Chaos theory</span> Field of mathematics

Chaos theory is an interdisciplinary area of scientific study and branch of mathematics focused on underlying patterns and deterministic laws of dynamical systems that are highly sensitive to initial conditions, and were once thought to have completely random states of disorder and irregularities. Chaos theory states that within the apparent randomness of chaotic complex systems, there are underlying patterns, interconnection, constant feedback loops, repetition, self-similarity, fractals, and self-organization. The butterfly effect, an underlying principle of chaos, describes how a small change in one state of a deterministic nonlinear system can result in large differences in a later state. A metaphor for this behavior is that a butterfly flapping its wings in Texas can cause a tornado in Brazil.

<span class="mw-page-title-main">Dynamical system</span> Mathematical model of the time dependence of a point in space

In mathematics, a dynamical system is a system in which a function describes the time dependence of a point in an ambient space, such as in a parametric curve. Examples include the mathematical models that describe the swinging of a clock pendulum, the flow of water in a pipe, the random motion of particles in the air, and the number of fish each springtime in a lake. The most general definition unifies several concepts in mathematics such as ordinary differential equations and ergodic theory by allowing different choices of the space and how time is measured. Time can be measured by integers, by real or complex numbers or can be a more general algebraic object, losing the memory of its physical origin, and the space may be a manifold or simply a set, without the need of a smooth space-time structure defined on it.

<span class="mw-page-title-main">Feigenbaum constants</span> Mathematical constants related to chaotic behavior

In mathematics, specifically bifurcation theory, the Feigenbaum constants are two mathematical constants which both express ratios in a bifurcation diagram for a non-linear map. They are named after the physicist Mitchell J. Feigenbaum.

In mathematics, Sharkovskii's theorem, named after Oleksandr Mykolayovych Sharkovsky, who published it in 1964, is a result about discrete dynamical systems. One of the implications of the theorem is that if a discrete dynamical system on the real line has a periodic point of period 3, then it must have periodic points of every other period.

<span class="mw-page-title-main">Michael Berry (physicist)</span> British physicist

Sir Michael Victor Berry,, is a mathematical physicist at the University of Bristol, England.

<span class="mw-page-title-main">Ashoke Sen</span> Indian physicist (born 1956)

Ashoke Sen FRS is an Indian theoretical physicist and distinguished professor at the International Centre for Theoretical Sciences (ICTS), Bangalore. A former distinguished professor at the Harish-Chandra Research Institute, Allahabad, He is also an honorary fellow in National Institute of Science Education and Research (NISER), Bhubaneswar, India he is also a Morningstar Visiting professor at MIT and a distinguished professor at the Korea Institute for Advanced Study. His main area of work is string theory. He was among the first recipients of the Breakthrough Prize in Fundamental Physics "for opening the path to the realization that all string theories are different limits of the same underlying theory".

In dynamical systems theory, a period-doubling bifurcation occurs when a slight change in a system's parameters causes a new periodic trajectory to emerge from an existing periodic trajectory—the new one having double the period of the original. With the doubled period, it takes twice as long for the numerical values visited by the system to repeat themselves.

<span class="mw-page-title-main">King Juan Carlos University</span> University from Spain

Rey Juan Carlos University is a Spanish public research university located in the southern area of the Community of Madrid (Spain), with five campuses at Móstoles, Alcorcón, Vicálvaro, Aranjuez and Fuenlabrada.

<span class="mw-page-title-main">Lorenz system</span> System of ordinary differential equations with chaotic solutions

The Lorenz system is a system of ordinary differential equations first studied by mathematician and meteorologist Edward Lorenz. It is notable for having chaotic solutions for certain parameter values and initial conditions. In particular, the Lorenz attractor is a set of chaotic solutions of the Lorenz system. In popular media the "butterfly effect" stems from the real-world implications of the Lorenz attractor, namely that several different initial chaotic conditions evolve in phase space in a way that never repeats, so all chaos is unpredictable. This underscores that chaotic systems can be completely deterministic and yet still be inherently unpredictable over long periods of time. Because chaos continually increases in systems, we cannot predict the future of systems well. E.g., even the small flap of a butterfly’s wings could set the world on a vastly different trajectory, such as by causing a hurricane. The shape of the Lorenz attractor itself, when plotted in phase space, may also be seen to resemble a butterfly.

<span class="mw-page-title-main">John C. Mather</span> American astrophysicist and cosmologist (born 1946)

John Cromwell Mather is an American astrophysicist, cosmologist and Nobel Prize in Physics laureate for his work on the Cosmic Background Explorer Satellite (COBE) with George Smoot.

<span class="mw-page-title-main">Tien-Yien Li</span> American mathematician (1945-2020)

Tien-Yien Li (李天岩) was a University Distinguished Professor of Mathematics and University Distinguished Professor Emeritus at Michigan State University. There, he spent 42 years and supervised 26 Ph.D. dissertations.

<span class="mw-page-title-main">Leon O. Chua</span> American electrical engineer and computer scientist

Leon Ong Chua is an American electrical engineer and computer scientist. He is a professor in the electrical engineering and computer sciences department at the University of California, Berkeley, which he joined in 1971. He has contributed to nonlinear circuit theory and cellular neural network theory.

Lennart Ljung is a Swedish professor in the Chair of Control Theory at Linköping University since 1976. He is known for his pioneering research in system identification, and is regarded as a leading researcher in control theory.

<span class="mw-page-title-main">Miguel Ángel Fernández Sanjuán</span>

Miguel Angel Fernández Sanjuán is a Spanish Theoretical Physicist from Leon, Spain. He is known for his contributions in nonlinear dynamics, chaos theory, and control of chaos, and has published several scientific papers and popular news articles. He has supervised around 20 PhD students in Nonlinear Dynamics, Chaos and Complex Systems.

Guanrong Chen (陈关荣) or Ron Chen is a Chinese mathematician who made contributions to Chaos theory. He has been the chair professor and the founding director of the Centre for Chaos and Complex Networks at the City University of Hong Kong since 2000. Prior to that, he was a tenured full professor at the University of Houston, Texas. Chen was elected Member of the Academy of Europe in 2014, elected Fellow of The World Academy of Sciences in 2015, and elected IEEE Fellow in 1997. He is currently the editor-in-chief for the International Journal of Bifurcation and Chaos.

<span class="mw-page-title-main">Zeev Rudnick</span>

Zeev Rudnick or Ze'ev Rudnick is a mathematician, specializing in number theory and in mathematical physics, notably quantum chaos. Rudnick is a professor at the School of Mathematical Sciences and the Cissie and Aaron Beare Chair in Number Theory at Tel Aviv University.

Celso Grebogi is a Brazilian theoretical physicist who works in the area of chaos theory. He is one among the pioneers in the nonlinear and complex systems and chaos theory. Currently he works at the University of Aberdeen as the "Sixth Century Chair in Nonlinear and Complex Systems". He has done extensive research in the field of plasma physics before his work on the theory of dynamical systems. He and his colleagues have shown with a numerical example that one can convert a chaotic attractor to any one of numerous possible attracting time-periodic motions by making only small time-dependent perturbations of an available system parameter. This article is considered as one among the classic works in the control theory of chaos and their control method is known as the OGY method. He was listed in the 2016 Thomson Reuters Citation Laureates.

<span class="mw-page-title-main">Edward Ott</span> American physicist

Edward Ott is an American physicist most noted for his contributions to the development of chaos theory.

Muthusamy Lakshmanan is an Indian theoretical physicist currently working as Professor of Eminence at the Department of Nonlinear Dynamics of Bharathidasan University. Presently he is the DST-SERB National Science Chair awarded by Science and Engineering Research Board, Department of Science and Technology. He has held several research fellowships which included Raja Rammanna fellowship of Department of Atomic Energy, Alexander von Humboldt fellowship, Japan Society for the Promotion of Science fellowship, Royal Society Nuffield Foundation fellowship, and NASI-Senior Scientist Platinum Jubilee Fellowship. In the year 2021, on August 15, he was conferred with Dr. A. P. J Abdul Kalam Award by the Government of Tamil Nadu.

Michael C. Mackey is a Canadian-American biomathematician and Professor in the Department of Physiology of McGill University in Montreal, Quebec, Canada who holds the Joseph Morley Drake Emeritus Chair.

References

  1. "APS Fellow Archive". APS. Retrieved 17 September 2020.
  2. List of Fellows of the American Mathematical Society , retrieved 2013-09-01
  3. Doctor Honoris Causa degree from the Universidad Rey Juan Carlos, Madrid, Spain, archived from the original on 2018-06-15, retrieved 2017-07-25
  4. Doctor Honoris Causa degree from Le Havre University, Le Havre, France
  5. Thomson Reuters Citations Laureate in Physics
  6. T.Y. Li, and J.A. Yorke, Period Three Implies Chaos, American Mathematical Monthly 82, 985 (1975).
  7. Sharkovskii, A. N. (1964). "Co-existence of cycles of a continuous mapping of the line into itself". Ukrainian Math. J. 16: 61–71.
  8. Blanchard, F.; Glasner, E.; Kolyada, S.; Maass, A. (2002). "On Li–Yorke pairs". Journal für die reine und angewandte Mathematik . 547: 51–68.
  9. Akin, E.; Kolyada, S. (2003). "Li–Yorke sensitivity". Nonlinearity . 16 (4): 1421–1433. Bibcode:2003Nonli..16.1421A. doi:10.1088/0951-7715/16/4/313. S2CID   250751553.
  10. Collet, Pierre; Eckmann, Jean-Pierre (1980). Iterated Maps on the Interval as Dynamical Systems . Birkhäuser. ISBN   3-7643-3510-6.