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arXiv · 2012.10612

On boundedness of characteristic class via quasi-morphism

Morimichi Kawasaki·Shuhei Maruyama
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Abstract

In this paper, we characterize the second bounded characteristic classes of foliated bundles in terms of the non-descendible quasi-morphisms on the universal covering of the structure group. As its application, we study the boundedness of obstruction classes for (contact) Hamiltonian fibrations and show the non-existence of foliated structures on some Hamiltonian fibrations. Moreover, for any closed symplectic manifold, we show the non-triviality of the second bounded cohomology group of the Hamiltonian diffeomorphism group.

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Morimichi Kawasaki, Shuhei Maruyama. 2020-12-19. On boundedness of characteristic class via quasi-morphism. https://arxiv.org/abs/2012.10612

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