We prove that the minimal nontrivial finite quotient group of the mapping class group M-g of a closed orientable surface of genus g is the symplectic group PSp2g(Z(2)), for g = 3 and 4 (this might remain true, however, for arbitrary genus g > 2). We also discuss some results for arbitrary genus g.
机构:
Math Inst, Woodstock Rd, Oxford OX2 6GG, England
Stockholm Univ, Dept Math, SE-10691 Stockholm, SwedenMath Inst, Woodstock Rd, Oxford OX2 6GG, England