We construct crossed
homomorphisms of the groups of volume preserving diffeomorphisms of closed
manifolds with nontrivial first cohomology groups and give their applications to the
volume flux groups. Moreover, we see that they descend to crossed homomorphisms
of their isotopy groups. In the two dimensional case, we show that their restrictions
to Torelli groups are the first Johnson homomorphisms.
Keywords
crossed homomorphisms, volume preserving diffeomorphisms,
volume flux groups