In this paper, we construct quasi-morphisms on the group of symplectomorphisms of the closed disk D. These quasi-morphisms are extensions of the Ruelle invariant and Gambaudo-Ghys quasi-morphisms. As a corollary, we show that the second bounded cohomology H-b(2) (Symp(D)) is infinite dimensional. (C) 2021 Elsevier B.V. All rights reserved.
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