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Poisson Structures for PDEs Associated with Diffeomorphism Groups


Vasylkevych, Sergiy (2004) Poisson Structures for PDEs Associated with Diffeomorphism Groups. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/472S-D335.


We study Poisson and Lie-Poisson structures on the diffeomorphism groups with a smooth metric spray in connection with dynamics of nonlinear PDEs. In particular, we provide a precise analytic sense in which the time t map for the Euler equations of an ideal fluid in a region of Rⁿ (or on a smooth compact n-manifold with a boundary) is a Poisson map relative to the Lie-Poisson bracket associated with the group of volume preserving diffeomorphisms. The key difficulty in finding a suitable context for that arises from the fact that the integral curves of Euler equations are not differentiable on the Lie algebra of divergence free vector fields of Sobolev class Hs. We overcome this obstacle by utilizing the smoothness that one has in Lagrangian representation and carefully performing a non-smooth Lie-Poisson reduction procedure on the appropriate functional classes.

This technique is generalized to an arbitrary diffeomorphism group possessing a smooth spray. The applications include the Camassa-Holm equation on S¹, the averaged Euler and EPDiff equations on the n-manifold with a boundary. In all cases we prove that time t map is Poisson on the appropriate Lie algebra of Hs vector fields, where s > n/2 + 1 for the Euler equation and s > n/2 + 2 otherwise.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:geometric PDE; Hamiltonian dynamics; infinitedimensional manifold
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Mathematics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Marsden, Jerrold E.
Thesis Committee:
  • Marsden, Jerrold E. (chair)
  • Borodin, Alexei
  • Denissov, S.
  • Kaloshin, Vadim
Defense Date:9 April 2004
Non-Caltech Author Email:sergiy.vasylkevych (AT)
Record Number:CaltechETD:etd-05212004-052003
Persistent URL:
Vasylkevych, Sergiy0000-0003-1878-1979
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1910
Deposited By: Imported from ETD-db
Deposited On:21 May 2004
Last Modified:22 Jan 2021 01:14

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