February 1, 2019 at 11:00 pm

Math-Biology Seminar | Role of Limsup in Definition of Topological Entropy, Feb. 5

Dr. Winfried Just, portrait

Dr. Winfried Just

The Dynamical Systems and Mathematical Biology Seminar presents Dr. Winfried Just discussing “On the role of limsup in the definition of topological entropy–an alternative view of the construction” on Tuesday, Feb. 5, from 3:05 to 4 p.m., in Morton 326.

Just is Professor of Mathematics at Ohio University.

Abstract: Topological entropy measures the complexity of a dynamical system. Two of the classical textbook definitions use a limit superior.  It had been conjectured for almost 50 years that this limit superior cannot be replaced by a limit, but an actual counterexample was constructed only in 2017 by the speaker and our former Ph.D. student Ying Xin.  The original construction of the counterexample is very complex and does not seem amenable to a short and simple description.  In this talk an alternative view of the construction will be presented in the hope that it can elucidate the main ideas within the confines of one seminar presentation.  As an added bonus, the revised construction proves a slightly stronger result.

Leave a Reply

Your email address will not be published. Required fields are marked *