%0 Journal Article %T Characteristic classes of foliated surface bundles with area-preserving holonomy %A D. Kotschick %A S. Morita %J Mathematics %D 2004 %I arXiv %X Making use of the extended flux homomorphism on the group of symplectomorphisms of a closed oriented surface of genus at least 2, we introduce new characteristic classes of foliated surface bundles with symplectic, equivalently area-preserving, total holonomy. These characteristic classes are stable with respect to the genus and we show that they are highly non-trivial. We also prove that the second homology of the group of Hamiltonian symplectomorphisms equipped with the discrete topology is very large. %U http://arxiv.org/abs/math/0409214v2