The heat flows and harmonic maps of complete noncompact Riemannian manifolds.
Sia un grupo di Lie compatto e semplice. Sia la più piccola orbita nilpotente non-banale nell'algebra di Lie complessa . Si presenta una costruzione diretta di teoria di Lie delle metriche iperKahler su con potenziale Kahleriano -invariante e compatibili con la forma simplettica complessa di Kostant-Kirillov-Souriau. In particolare si ottengono le metriche iperKahler dei fibrati associati sugli spazi di Wolf (spazi simmetrici quaternionali a curvatura scalare positiva).
Let be a presymplectic groupoid. In this paper we characterize the infinitesimal counter part of the tangent presymplectic groupoid of higher order, where is the tangent groupoid of higher order and is the complete lift of higher order of presymplectic form .
A Theorem is proved that gives intrinsic necessary and sufficient conditions for the integrability of a zero-deformable field of endomorphisms. The Theorem is proved by reducing to a special case in which the endomorphism field is nilpotent. Many arguments used in the derivation of similar results are simplified, principally by means of using quotient rather than subspace constructions.