Lie bialgebras of complex type and associated Poisson Lie groups

ADRIAN ANDRADA; MARÍA LAURA BARBERIS; GABRIELA OVANDO

JOURNAL OF GEOMETRY AND PHYSICS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2008 vol. 58 p. 1310 - 1328

0393-0440

In this work we study a particular class of Lie bialgebras arising from Hermitian structures on Lie algebras such that the metric is ad-invariant. We will refer to them as Lie bialgebras of complex type. These give rise to Poisson Lie groups G whose corresponding duals G* are complex Lie groups. We also prove that a Hermitian structure on g with ad-invariant metric induces a structure of the same type on the double Lie algebra Dg = g+g*, with respect to the canonical ad-invariant metric of neutral signature on Dg. We show how to construct a 2n-dimensional Lie bialgebra of complex type starting with one of dimension 2(n-2), n>3. This allows us to determine all solvable Lie algebras of dimension  at most 6 admitting a Hermitian structure with ad-invariant metric.We exhibit some examples in dimensions 4 and 6, including two one-parameter families, where we identify the Lie-Poisson structures on the associated simply connected Lie groups, obtaining also their symplectic foliations.