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Invariant orders in Lie groups

Neeb, Karl-Hermann (1991)

Proceedings of the Winter School "Geometry and Physics"

[For the entire collection see Zbl 0742.00067.]The author formulates several theorems about invariant orders in Lie groups (without proofs). The main theorem: a simply connected Lie group G admits a continuous invariant order if and only if its Lie algebra L ( G ) contains a pointed invariant cone. V. M. Gichev has proved this theorem for solvable simply connected Lie groups (1989). If G is solvable and simply connected then all pointed invariant cones W in L ( G ) are global in G (a Lie wedge W L ( G ) is said to...

Invariant prolongation of BGG-operators in conformal geometry

Matthias Hammerl (2008)

Archivum Mathematicum

BGG-operators form sequences of invariant differential operators and the first of these is overdetermined. Interesting equations in conformal geometry described by these operators are those for Einstein scales, conformal Killing forms and conformal Killing tensors. We present a deformation procedure of the tractor connection which yields an invariant prolongation of the first operator. The explicit calculation is presented in the case of conformal Killing forms.

Invariant subspaces in higher order jet prolongations of a fibred manifold

Miroslav Doupovec, Alexandr Vondra (2000)

Czechoslovak Mathematical Journal

We present a generalization of the concept of semiholonomic jets within the framework of higher order prolongations of a fibred manifold. In this respect, a compilation of our 2-fibred manifold approach with the methods of natural operators theory is used.

Invariant torsion and G2-metrics

Diego Conti, Thomas Bruun Madsen (2015)

Complex Manifolds

We introduce and study a notion of invariant intrinsic torsion geometrywhich appears, for instance, in connection with the Bryant-Salamon metric on the spinor bundle over S3. This space is foliated by sixdimensional hypersurfaces, each of which carries a particular type of SO(3)-structure; the intrinsic torsion is invariant under SO(3). The last condition is sufficient to imply local homogeneity of such geometries, and this allows us to give a classification. We close the circle by showing that...

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...

Invariant vector fields of Hamiltonians

Jacek Dębecki (1998)

Archivum Mathematicum

A complete classification of natural transformations of Hamiltonians into vector fields on symplectic manifolds is given herein.

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