350 research outputs found
Stress-Energy-Momentum of Affine-Metric Gravity. Generalized Komar Superportential
In case of the Einstein's gravitation theory and its first order Palatini
reformulation, the stress-energy-momentum of gravity has been proved to reduce
to the Komar superpotential. We generalize this result to the affine-metric
theory of gravity in case of general connections and arbitrary Lagrangian
densities invariant under general covariant transformations. In this case, the
stress-energy-momentum of gravity comes to the generalized Komar superpotential
depending on a Lagrangian density in a precise way.Comment: 12 pp, LaTeX fil
Noether's second theorem in a general setting. Reducible gauge theories
We prove Noether's direct and inverse second theorems for Lagrangian systems
on fiber bundles in the case of gauge symmetries depending on derivatives of
dynamic variables of an arbitrary order. The appropriate notions of reducible
gauge symmetries and Noether's identities are formulated, and their equivalence
by means of certain intertwining operator is proved.Comment: 20 pages, to be published in J. Phys. A (2005
The Liouville-Arnold-Nekhoroshev theorem for non-compact invariant manifolds
Under ceratin conditions, generalized action-angle coordinates can be
introduced near non-compact invariant manifolds of completely and partially
integrable Hamiltonian systems.Comment: 8 page
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