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François Gay-Balmaz

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Related publications (34)

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Reduced Variational Formulations in Free Boundary Continuum Mechanics

Tudor Ratiu, François Gay-Balmaz

We present the material, spatial, and convective representations for elasticity and fluids with a free boundary from the Lagrangian reduction point of view, using the material and spatial symmetries of these systems. The associated constrained variational ...

Springer-Verlag2012

Reduced Lagrangian and Hamiltonian formulations of Euler-Yang-Mills fluids

Tudor Ratiu, François Gay-Balmaz

The Lagrangian and Hamiltonian structures for an ideal gauge-charged fluid are determined. Using a Kaluza-Klein point of view, the equations of motion are obtained by Lagrangian and Poisson reductions associated to the automorphism group of a principal bun ...

2008

Invariant Higher-Order Variational Problems II

Tudor Ratiu, François Gay-Balmaz

Motivated by applications in computational anatomy, we consider a second-order problem in the calculus of variations on object manifolds that are acted upon by Lie groups of smooth invertible transformations. This problem leads to solution curves known as ...

Springer Verlag2012

Higher order Lagrange-Poincar, and Hamilton-Poincar, reductions

Tudor Ratiu, François Gay-Balmaz

Motivated by the problem of longitudinal data assimilation, e.g., in the registration of a sequence of images, we develop the higher-order framework for Lagrangian and Hamiltonian reduction by symmetry in geometric mechanics. In particular, we obtain the r ...

2011

The geometry of the universal Teichmuller space and the Euler-Weil-Petersson equation

Tudor Ratiu, François Gay-Balmaz

On the identity component of the universal Teichmuller space endowed with the Takhtajan-Teo topology, the geodesics of the Weil Petersson metric are shown to exist for all time. This component is naturally a subgroup of the quasisymmetric homeomorphisms of ...

Elsevier2015

The Geometric Nature of the Flaschka Transformation

Tudor Ratiu, François Gay-Balmaz

We show that the Flaschka map, originally introduced to analyze the dynamics of the integrable Toda lattice system, is the inverse of a momentum map. We discuss the geometrical setting of the map and apply it to the generalized Toda lattice systems on semi ...

Springer Verlag2017

Invariant Higher-Order Variational Problems

Tudor Ratiu, François Gay-Balmaz

We investigate higher-order geometric k-splines for template matching on Lie groups. This is motivated by the need to apply diffeomorphic template matching to a series of images, e.g., in longitudinal studies of Computational Anatomy. Our approach formulat ...

2012

Geometry of nonabelian charged fluids

Tudor Ratiu, François Gay-Balmaz

The goal of this paper is to derive the Hamiltonian structure of polarized and magnetized Euler-Maxwell fluids by reduction of the canonical symplectic form on phase space, and to generalize the dynamics to the nonabelian case. The Hamiltonian function we ...

2011

Poisson reduction and the Hamiltonian structure of the Euler-Yang-Mills equations

Tudor Ratiu, François Gay-Balmaz

The problem treated here is to find the Hamiltonian structure for an ideal gauge-charged fluid. Using a Kaluza-Klein point of view, we obtain the non-canonical Poisson bracket and the motion equations by a Poisson reduction involving the automorphism group ...

American Mathematical Society, P.O. Box 6248 Ms. Phoebe Murdock, Providence, Ri 02940 Usa2008

Euler-Poincare Approaches to Nematodynamics

Tudor Ratiu, François Gay-Balmaz, Cesare Tronci

Nematodynamics is the orientation dynamics of flowless liquid-crystals. We show how Euler-Poincar, reduction produces a unifying framework for various theories, including Ericksen-Leslie, Luhiller-Rey, and Eringen's micropolar theory. In particular, we sho ...

Springer Netherlands2012

Multisymplectic Lie group variational integrator for a geometrically exact beam in R3

Tudor Ratiu, François Gay-Balmaz, François Marie Alain Demoures

In this paper we develop, study, and test a Lie group multisymplectic integra- tor for geometrically exact beams based on the covariant Lagrangian formulation. We exploit the multisymplectic character of the integrator to analyze the energy and momentum ma ...

Elsevier2014

Group actions on chains of Banach manifolds and applications to fluid dynamics

Tudor Ratiu, François Gay-Balmaz

2007

Equivalent Theories of Liquid Crystal Dynamics

Tudor Ratiu, François Gay-Balmaz, Cesare Tronci

There are two competing descriptions of nematic liquid crystal dynamics: the Ericksen-Leslie director theory and the Eringen micropolar approach. Up to this day, these two descriptions have remained distinct in spite of several attempts to show that the mi ...

Springer Verlag2013

The Lie-Poisson structure of the LAE-$\alpha$ equation

Tudor Ratiu, François Gay-Balmaz

2005