Hermitian structures on cotangent bundles of four dimensional solvable Lie groups
arXiv:math/0604608
Abstract
We study hermitian structures, with respect to the standard neutral metric on the cotangent bundle of a 2n-dimensional Lie group , which are left invariant with respect to the Lie group structure on induced by the coadjoint action. These are in one-to-one correspondence with left invariant generalized complex structures on . Using this correspondence and results of Cavalcanti-Gualtieri and Fernández-Gotay-Gray, it turns out that when is nilpotent and four or six dimensional, the cotangent bundle always has a hermitian structure. However, we prove that if is a four dimensional solvable Lie group admitting neither complex nor symplectic structures, then has no hermitian structure or, equivalently, has no left invariant generalized complex structure.
26 pages. Typos corrected