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%%%%% Author : Guido Mislin %%%%%
%%%%% Title : Mapping class groups, characteristic classes %%%%%
%%%%% and Bernoulli numbers %%%%%
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%%%%% Address : G. Mislin %%%%%
%%%%% Department of Mathematics %%%%%
%%%%% Ohio State University %%%%%
%%%%% Columbus, Ohio 43210, USA %%%%%
%%%%% (e-mail: mislin@math.ohio-state.edu) %%%%%
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%%%%% or : %%%%%
%%%%% Department of Mathematics %%%%%
%%%%% ETH, 8092 Zuerich, Switzerland %%%%%
%%%%% (e-mail: mislin@math.ethz.ch) %%%%%
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This is a survey on the cohomology of the mapping class group
of a closed oriented connected surface.
In section 5 we compute the order of the Euler class e_{2g}(\Gamma_G)
of the flat bundle over the classifying space of the mapping
class group \Gamma_g, which is associated to the natural action of the
natural action of \Gamma_g on the first homology group of the surface.
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