Thursday, April 20
Time: 4:00 p.m.
Location: 114 McAllister Building
Name: Alexander Shnirelman
Affiliation: Concordia University
Title: The mystery of 2-d fluid
Abstract: Some important natural flows can be regarded as 2-dimensional; such are the large-scale atmosphere and ocean flows, and even more the atmospheric motions in other planets. Their strange properties are known for many years and described as ''Inverse energy cascade'', ''Negative viscosity'', ''Decreasing Entropy'' etc. All these names relate to the fact that in the typical 2-d flows the energy is transferred from the small-scale motions to the large-scale ones which is opposite to the 3-d turbulence. In the talk this phenomenon is considered from different viewpoints. The inverse cascade can be naturally described in the framework of the fluid kinematics (i.e. geometry of the configuration space), dynamics (the properties of the underlying dynamical system), and statistics (in terms of the appropriate entropy). Beside a few rigorous results, some hypotheses will be discussed. No special knowledge is assumed.