21 Settembre, 2016 16:30 oclock

Seminario Matematico e Fisico di Milano

Vortex filament dynamics

Walter Craig, McMaster University

Sala di rappresentanza, Dipartimento di Matematica, Università degli Studi, Via C. Saldini 50

The evolution of vortex filaments in three dimensions is an important problem in mathematical hydrodynamics. It appears in questions on solutions of the Euler equations as well as in the fine structure of vortex filamentation in a superfluid. It is also a setting in the analysis of partial differential equations with a compelling analogy to Hamiltonian dynamical systems. I will give an analysis of a system of model equations for the dynamics of near-parallel vortex filaments in a three dimensional fluid. These equations can be formulated as a Hamiltonian system of partial differential equations, and the talk will describe some aspects of a phase space analysis of solutions, including the construction of periodic and quasi-periodic orbits via a version of KAM theory for PDEs, and a topological principle to count multiplicity of solutions. This is ongoing joint work with L. Corsi (McMaster and Georgia Tech), C. Garcia (UNAM) and C.-R. Yang (McMaster and Shantou Univ.)