Strongly degenerate homogeneous pseudo-K\"ahler structures of linear   type and complex plane waves
  We study the class $\mathcal{K}_{2}+\mathcal{K}_{4}$ of homogeneous pseudo-K\"ahler structures in the strongly degenerate case. The local form and the holonomy of a pseudo-K\"ahler manifold admitting such a structure is obtained, leading to a possible complex generalization of homogeneous plane waves. The same question is tackled in the case of pseudo-hyper-K\"ahler and pseudo-quaternion K\"ahler manifolds. 
M. Castrill\'on L\'opez, I. Luj\'an
math.DG