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Invariant tracking

Philippe Martin, Pierre Rouchon, Joachim Rudolph (2004)

ESAIM: Control, Optimisation and Calculus of Variations

The problem of invariant output tracking is considered: given a control system admitting a symmetry group G , design a feedback such that the closed-loop system tracks a desired output reference and is invariant under the action of G . Invariant output errors are defined as a set of scalar invariants of G ; they are calculated with the Cartan moving frame method. It is shown that standard tracking methods based on input-output linearization can be applied to these invariant errors to yield the required...

Invariant tracking

Philippe Martin, Pierre Rouchon, Joachim Rudolph (2010)

ESAIM: Control, Optimisation and Calculus of Variations

The problem of invariant output tracking is considered: given a control system admitting a symmetry group G, design a feedback such that the closed-loop system tracks a desired output reference and is invariant under the action of G. Invariant output errors are defined as a set of scalar invariants of G; they are calculated with the Cartan moving frame method. It is shown that standard tracking methods based on input-output linearization can be applied to these invariant errors to yield the...

Isospectrality for quantum toric integrable systems

Laurent Charles, Álvaro Pelayo, San Vũ Ngoc (2013)

Annales scientifiques de l'École Normale Supérieure

We give a full description of the semiclassical spectral theory of quantum toric integrable systems using microlocal analysis for Toeplitz operators. This allows us to settle affirmatively the isospectral problem for quantum toric integrable systems: the semiclassical joint spectrum of the system, given by a sequence of commuting Toeplitz operators on a sequence of Hilbert spaces, determines the classical integrable system given by the symplectic manifold and commuting Hamiltonians. This type of...

Jordan obstruction to the integrability of Hamiltonian systems with homogeneous potentials

Guillaume Duval, Andrzej J. Maciejewski (2009)

Annales de l’institut Fourier

In this paper, we consider the natural complex Hamiltonian systems with homogeneous potential V ( q ) , q ∈ ℂ n , of degree k ∈ ℤ ☆ . The known results of Morales and Ramis give necessary conditions for the complete integrability of such systems. These conditions are expressed in terms of the eigenvalues of the Hessian matrix V ′ ′ ( c ) calculated at a non-zero point c ∈ ℂ n , such that V ′ ( c ) = c . The main aim of this paper is to show that there are other obstructions for the integrability which appear if the matrix V ′ ′ ( c ) is not diagonalizable....

KAM Tori and Quantum Birkhoff Normal Forms

Georgi Popov (1999/2000)

Séminaire Équations aux dérivées partielles

This talk is concerned with the Kolmogorov-Arnold-Moser (KAM) theorem in Gevrey classes for analytic hamiltonians, the effective stability around the corresponding KAM tori, and the semi-classical asymptotics for Schrödinger operators with exponentially small error terms. Given a real analytic Hamiltonian H close to a completely integrable one and a suitable Cantor set Θ defined by a Diophantine condition, we find a family Λ ω , ω ∈ Θ , of KAM invariant tori of H with frequencies ω ∈ Θ which is Gevrey smooth with...

Killing's equations in dimension two and systems of finite type

Gerard Thompson (1999)

Mathematica Bohemica

A PDE system is said to be of finite type if all possible derivatives at some order can be solved for in terms lower order derivatives. An algorithm for determining whether a system of finite type has solutions is outlined. The results are then applied to the problem of characterizing symmetric linear connections in two dimensions that possess homogeneous linear and quadratic integrals of motions, that is, solving Killing's equations of degree one and two.

Currently displaying 441 – 460 of 1123