Mini Course  by  Vitaly Bergelson

                                                       

Ergodic Ramsey Theory:

Dynamical Methods at the service of Number Theory

and Combinatorics

 

August 20~24, 2007

 

Ajou University & Korea Institute for Advanced Study

 

The lectures will be devoted to the presentation of some of the numerous and multifaceted connections which exist between Ergodic Theory, Combinatorics and Number Theory. We will start with reviewing some applications of the Poincare recurrence theorem to such diverse algebraic results as Hilbert's irreducibility theorem and Dickson-Schur theorem on the solvability of Fermat equation over finite fields. We will move then to the discussion of Furstenberg's ergodic approach to Szemeredi's theorem on arithmetic progressions. Furstenberg's proof was a starting point of new exciting developments and we will discuss some of them, including the polynomial Szemeredi theorem, multiple recurrence theorems for general groups and the role of dynamical systems on nil-manifolds in the study of multiple recurrence. Some of the recent results rely heavily on methods of topological algebra in the Stone-Cech compactifications and we will review some of these methods. We will also discuss the ergodic underpinnings of recent spectacular theorem of Green and Tao on arithmetic progressions in primes and its recent polynomial extension by Tao and Ziegler. Finally, we will give a review of some natural open problems and promising directions of research.¡¡

 

 

Prelude

621 Paldal-Kwan, Ajou University

Monday

 

10:30-12:20

Young Ho Ahn (Mokpo University)

Introduction to Ergodic Theory I

Lunch

14:30-16:20

Dong Han Kim (Suwon University)

Introduction to Ergodic Theory II

 

 

Mini Course by Bergelson

Room 1423, KIAS

 

Tuesday

 

10:30-11:20

Ergodic Ramsey Theory I:

Overview of some classical results in Ramsey theory

11:30-12:20

Ergodic Ramsey Theory II:

Partition Ramsey theory and topological dynamics

Lunch

14:30-15:20

Ergodic Ramsey Theory III:

Furstenberg¡¯s ergodic approach to Szemeredi¡¯s theorem on arithmetic progressions

15: 30-16:20

 

Wednesday

 

10:30-11:20

Ergodic Ramsey Theory IV:

Polynomial extensions of Szemeredi theorem

11:30-12:20

Ergodic Ramsey Theory V:

Stone-Cech compactification of integers and Hindman¡¯s theorem

Lunch

14:30-15:20

Ergodic Ramsey Theory VI:

IP ergodic theory versus Cesaro ergodic theory

15: 30-16:20

 

Thursday

 

10:30-11:20

Ergodic Ramsey Theory VII:

Bohr compactification of integers and sumsets

11:30-12:20

Ergodic Ramsey Theory VIII:

New trends: multiple recurrence in nilpotent and amenable set-up

Lunch

14:30-15:20

Poo-Sung Park (KIAS)

HKK's 2n+3 Theorem for Quadratic Forms (What the Ergodic theory improved.)

 

 

Colloquium

Room 1423, KIAS

Thursday 16:30-17:30

Ergodic Ramsey Theory and Patterns in Primes

(See Abstract Below)

 

 

Epilogue

Room 1423, KIAS

Friday 10:30-12:20

Open problems and conjectures

 

 

Colloquium: Ergodic Ramsey Theory and Patterns in Primes

 

Abstract

 

Szemeredi's theorem on arithmetic progressions states that any set of positive upper density in N contains arbitrarily long arithmetic progressions. Furstenberg's ergodic proof of Szemeredi's theorem has revealed the dynamic content of Szemeredi's theorem and has paved the way to numerous spectacular generalizations and extensions, most of which do not have as yet a conventional proof. We will survey some of important developments and conclude with the discussion of the recent work of Tao and Ziegler in which they merge the theorem of Green and Tao on arithmetic progressions in primes with the polynomial extension of Szemeredi's theorem due to Bergelson and Leibman.

 

Note: This colloquial talk is also given in 621 Paldal-Kwan at Ajou University on August 29, 2007.

 

 

 

References

 

*       H. Furstenberg: Recurrence in Ergodic Theory and Combinatorial Number Theory

*       P. Walters: An Introduction to Ergodic Theory

*       W. Parry: Topics in Ergodic Theory

*       K. Petersen: Ergodic Theory

*       T. Tao and V.H. Vu: Additive Combinatorics

 

 

 

 

Organizers:          Kyewon Koh Park (Ajou University)

                              Soon-Yi Kang (Korea Institute for Advanced Study)

 

Local organizer:  Poo-Sung Park (Korea Institute for Advanced Study)

 

Sponsors:             Korea Institute for Advanced Study

                              Department of Mathematics (BK 21 Program), Ajou University

 

     


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