Leonid Bunimovich
![](../I/m/Leonid_Bunimovic.jpg)
(photo from MFO)
Leonid Bunimovich is a Soviet and American mathematician, who specializes in dynamical systems. He is known for discovery of a fundamental mechanism of chaos (hyperbolicity) in Dynamical systems, which is called mechanism of defocusing. The most famous class of chaotic dynamical systems of this type Dynamical billiards are focusing chaotic billiards (e.g., the "Bunimovich stadium" and the "Bunimovich flowers"). More recently he introduced so called Bunimovich mushrooms, which are visual examples of billiards with mixed regular and chaotic dynamics. In many labs over the world were built experimental devices in the form of various Bunimovich billiards. He received bachelor's degree in 1967 and PhD in 1973 from the University of Moscow. His thesis adviser was Yakov G. Sinai. In 1986 he was awarded Doctor of Sciences degree in "Theoretical and Mathematical Physics". Bunimovich is a Regents' Professor of Mathematics at the Georgia Institute of Technology. He has studied numerous topics in pure and applied dynamical systems, mathematical physics, probability theory and mathematical biology. Notably he introduced and investigated Hierarchical models of Human populations, (Bunimovich) Traps of internal waves in non-homogeneous stratified fluids and Deterministic walks in random environments.