Abstract
In this paper we define a –valued class function on the mapping class group of a surface of genus with two boundary components. Let be a –bundle over a pair of pants . Gluing to the product of an annulus and along the boundaries of each fiber, we obtain a closed surface bundle over . We have another closed surface bundle by gluing to the product of and two disks.
The sign of our class function cobounds the 2–cocycle on defined by the difference of the signature of these two surface bundles over .
Citation
Masatoshi Sato. "A class function on the mapping class group of an orientable surface and the Meyer cocycle." Algebr. Geom. Topol. 8 (3) 1647 - 1665, 2008. https://doi.org/10.2140/agt.2008.8.1647
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