16 research outputs found
SO(3)-Structures on 8-manifolds
We study Riemannian 8-manifolds with an infinitesimal action of SO(3) by
which each tangent space breaks into irreducible spaces of dimensions 3 and 5.
The relationship with quaternionic, almost product- and PSU-geometry is
thoroughly explained using representation-theoretical arguments.Comment: 19 pages, 2 figure
Complex homothetic foliations on K\"ahler manifolds
We obtain a local classification of complex homothetic foliations on Kaehler
manifolds by complex curves. This is used to construct almost Kaehler,
Ricci-flat metrics subject to additional curvature properties.Comment: Final version, up to typos. To appear in BLM
Systems of symplectic forms on four-manifolds
We study almost Hermitian 4-manifolds with holonomy algebra, for the
canonical Hermitian connection, of dimension at most one. We show how
Riemannian 4-manifolds admitting five orthonormal symplectic forms fit therein
and classify them. In this set-up we also fully describe almost Kaehler
4-manifolds.Comment: Final version, to appear in Annali di SNS.added thm. 5.