Ergodic theory

Ergodicity

In mathematics, ergodicity expresses the idea that a point of a moving system, either a dynamical system or a stochastic process, will eventually visit all parts of the space that the system moves in, in a uniform and random sense. This implies that the average behavior of the system can be deduced from the trajectory of a "typical" point. Equivalently, a sufficiently large collection of random samples from a process can represent the average statistical properties of the entire process. Ergodicity is a property of the system; it is a statement that the system cannot be reduced or factored into smaller components. Ergodic theory is the study of systems possessing ergodicity. Ergodic systems occur in a broad range of systems in physics and in geometry. This can be roughly understood to be due to a common phenomenon: the motion of particles, that is, geodesics on a hyperbolic manifold are divergent; when that manifold is compact, that is, of finite size, those orbits return to the same general area, eventually filling the entire space. Ergodic systems capture the common-sense, every-day notions of randomness, such that smoke might come to fill all of a smoke-filled room, or that a block of metal might eventually come to have the same temperature throughout, or that flips of a fair coin may come up heads and tails half the time. A stronger concept than ergodicity is that of mixing, which aims to mathematically describe the common-sense notions of mixing, such as mixing drinks or mixing cooking ingredients. The proper mathematical formulation of ergodicity is founded on the formal definitions of measure theory and dynamical systems, and rather specifically on the notion of a measure-preserving dynamical system. The origins of ergodicity lie in statistical physics, where Ludwig Boltzmann formulated the ergodic hypothesis. (Wikipedia).

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Ergodicity in Chaotic Self-Gravitating Systems

https://www.sns.ias.edu/stellar-dynamics-workshop/schedule More videos on http://video.ias.edu

From playlist Natural Sciences

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Quantum Ergodicity for the Uninitiated - Zeev Rudnick

Zeev Rudnick Tel Aviv University; Member, School of Mathematics October 26, 2015 https://www.math.ias.edu/seminars/abstract?event=47561 A key result in spectral theory linking classical and quantum mechanics is the Quantum Ergodicity theorem, which states that in a system in which the cl

From playlist Members Seminar

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Karma Dajani - An introduction to Ergodic Theory of Numbers (Part 2)

In this course we give an introduction to the ergodic theory behind common number expansions, like expansions to integer and non-integer bases, Luroth series and continued fraction expansion. Starting with basic ideas in ergodic theory such as ergodicity, the ergodic theorem and natural ex

From playlist École d’été 2013 - Théorie des nombres et dynamique

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Karma Dajani - An introduction to Ergodic Theory of Numbers (Part 1)

In this course we give an introduction to the ergodic theory behind common number expansions, like expansions to integer and non-integer bases, Luroth series and continued fraction expansion. Starting with basic ideas in ergodic theory such as ergodicity, the ergodic theorem and natural ex

From playlist École d’été 2013 - Théorie des nombres et dynamique

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Karma Dajani - An introduction to Ergodic Theory of Numbers (Part 3)

In this course we give an introduction to the ergodic theory behind common number expansions, like expansions to integer and non-integer bases, Luroth series and continued fraction expansion. Starting with basic ideas in ergodic theory such as ergodicity, the ergodic theorem and natural ex

From playlist École d’été 2013 - Théorie des nombres et dynamique

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Uri Bader - 2/4 Algebraic Representations of Ergodic Actions

Ergodic Theory is a powerful tool in the study of linear groups. When trying to crystallize its role, emerges the theory of AREAs, that is Algebraic Representations of Ergodic Actions, which provides a categorical framework for various previously studied concepts and methods. Roughly, this

From playlist Uri Bader - Algebraic Representations of Ergodic Actions

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Amos Nevo: Representation theory, effective ergodic theorems, and applications - Lecture 1

Find this video and other talks given by worldwide mathematicians on CIRM's Audiovisual Mathematics Library: http://library.cirm-math.fr. And discover all its functionalities: - Chapter markers and keywords to watch the parts of your choice in the video - Videos enriched with abstracts, b

From playlist Dynamical Systems and Ordinary Differential Equations

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Amos Nevo: Representation theory, effective ergodic theorems, and applications - Lecture 4

Find this video and other talks given by worldwide mathematicians on CIRM's Audiovisual Mathematics Library: http://library.cirm-math.fr. And discover all its functionalities: - Chapter markers and keywords to watch the parts of your choice in the video - Videos enriched with abstracts, b

From playlist Dynamical Systems and Ordinary Differential Equations

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Uri Bader - 3/4 Algebraic Representations of Ergodic Actions

Ergodic Theory is a powerful tool in the study of linear groups. When trying to crystallize its role, emerges the theory of AREAs, that is Algebraic Representations of Ergodic Actions, which provides a categorical framework for various previously studied concepts and methods. Roughly, this

From playlist Uri Bader - Algebraic Representations of Ergodic Actions

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Amine Marrakchi: Ergodic theory of affine isometric actions on Hilbert spaces

The Gaussian functor associates to every orthogonal representation of a group G on a Hilbert space, a probability measure preserving action of G called a Gaussian action. This construction is a fundamental tool in ergodic theory and is the source of a large and interesting class of probabi

From playlist Probability and Statistics

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Amos Nevo: Representation theory, effective ergodic theorems, and applications - Lecture 3

Find this video and other talks given by worldwide mathematicians on CIRM's Audiovisual Mathematics Library: http://library.cirm-math.fr. And discover all its functionalities: - Chapter markers and keywords to watch the parts of your choice in the video - Videos enriched with abstracts, b

From playlist Dynamical Systems and Ordinary Differential Equations

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Amos Nevo: Representation theory, effective ergodic theorems, and applications - Lecture 2

Find this video and other talks given by worldwide mathematicians on CIRM's Audiovisual Mathematics Library: http://library.cirm-math.fr. And discover all its functionalities: - Chapter markers and keywords to watch the parts of your choice in the video - Videos enriched with abstracts, b

From playlist Dynamical Systems and Ordinary Differential Equations

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Bryna Kra : Multiple ergodic theorems: old and new - lecture 1

Abstract : The classic mean ergodic theorem has been extended in numerous ways: multiple averages, polynomial iterates, weighted averages, along with combinations of these extensions. I will give an overview of these advances and the different techniques that have been used, focusing on co

From playlist Dynamical Systems and Ordinary Differential Equations

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