We focus on two kinds of infinite index subgroups of the mapping class group of a surface associated with a Lagrangian submodule of the first homology of a surface. These subgroups, called Lagrangian mapping class groups, are known to play important roles in the interaction between the mapping class group and finite-type invariants of 3–manifolds. In this paper, we discuss these groups from a group (co)homological point of view. The results include the determination of their abelianizations, lower bounds of the second homology and remarks on the (co)homology of higher degrees. As a byproduct of this investigation, we determine the second homology of the mapping class group of a surface of genus 3.
Keywords: mapping class group, Torelli group, Lagrangian filtration, Miller–Morita–Mumford class
Sakasai, Takuya  1
@article{10_2140_agt_2012_12_267,
author = {Sakasai, Takuya},
title = {Lagrangian mapping class groups from a group homological point of view},
journal = {Algebraic and Geometric Topology},
pages = {267--291},
year = {2012},
volume = {12},
number = {1},
doi = {10.2140/agt.2012.12.267},
url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2012.12.267/}
}
TY - JOUR AU - Sakasai, Takuya TI - Lagrangian mapping class groups from a group homological point of view JO - Algebraic and Geometric Topology PY - 2012 SP - 267 EP - 291 VL - 12 IS - 1 UR - http://geodesic.mathdoc.fr/articles/10.2140/agt.2012.12.267/ DO - 10.2140/agt.2012.12.267 ID - 10_2140_agt_2012_12_267 ER -
Sakasai, Takuya. Lagrangian mapping class groups from a group homological point of view. Algebraic and Geometric Topology, Tome 12 (2012) no. 1, pp. 267-291. doi: 10.2140/agt.2012.12.267
[1] , , , , Finite type invariants and fatgraphs, Adv. Math. 225 (2010) 2117
[2] , The cohomology ring of the group of dyed braids, Mat. Zametki 5 (1969) 227
[3] , Braids, links, and mapping class groups, 82, Princeton Univ. Press (1974)
[4] , On the equivalence of Heegaard splittings of closed, orientable 3–manifolds, from: "Knots, groups, and 3–manifolds (Papers dedicated to the memory of R. H. Fox)" (editor L P Neuwirth), Ann. of Math. Studies 84, Princeton Univ. Press (1975) 137
[5] , , , Calculating the image of the second Johnson–Morita representation, from: "Groups of diffeomorphisms" (editors R Penner, D Kotschick, T Tsuboi, N Kawazumi, T Kitano, Y Mitsumatsu), Adv. Stud. Pure Math. 52, Math. Soc. Japan (2008) 119
[6] , , The μ–invariant of 3–manifolds and certain structural properties of the group of homeomorphisms of a closed, oriented 2–manifold, Trans. Amer. Math. Soc. 237 (1978) 283
[7] , Stable real cohomology of arithmetic groups II, from: "Manifolds and Lie groups (Notre Dame, Ind., 1980)" (editors S Murakami, J Hano, K Okamoto, A Morimoto, H Ozeki), Progr. Math. 14, Birkhäuser (1981) 21
[8] , , , Irreducible Sp–representations and subgroup distortion in the mapping class group, Comment. Math. Helv. 86 (2011) 537
[9] , Cohomology of groups, 87, Springer (1982)
[10] , , , A functorial LMO invariant for Lagrangian cobordisms, Geom. Topol. 12 (2008) 1091
[11] , , A TQFT associated to the LMO invariant of three-dimensional manifolds, Comm. Math. Phys. 272 (2007) 601
[12] , , The diffeomorphism group of a compact Riemann surface, Bull. Amer. Math. Soc. 73 (1967) 557
[13] , , Finite type 3–manifold invariants, the mapping class group and blinks, J. Differential Geom. 47 (1997) 257
[14] , A presentation for the special automorphism group of a free group, J. Pure Appl. Algebra 33 (1984) 269
[15] , , Vanishing of universal characteristic classes for handlebody groups and boundary bundles, J. Homotopy Relat. Struct. 6 (2011) 103
[16] , The action of the handlebody group on the first homology group of the surface, Kyungpook Math. J. 46 (2006) 399
[17] , An abelian quotient of the mapping class group Ig, Math. Ann. 249 (1980) 225
[18] , Quadratic forms and the Birman–Craggs homomorphisms, Trans. Amer. Math. Soc. 261 (1980) 235
[19] , The structure of the Torelli group I : A finite set of generators for I, Ann. of Math. 118 (1983) 423
[20] , The structure of the Torelli group II : A characterization of the group generated by twists on bounding curves, Topology 24 (1985) 113
[21] , The structure of the Torelli group III : The abelianization of Ig, Topology 24 (1985) 127
[22] , , The second homology groups of mapping class groups of oriented surfaces, Math. Proc. Cambridge Philos. Soc. 134 (2003) 479
[23] , Pure braids, a new subgroup of the mapping class group and finite-type invariants of 3–manifolds, from: "Tel Aviv Topology Conference : Rothenberg Festschrift (1998)" (editors M Farber, W Lück, S Weinberger), Contemp. Math. 231, Amer. Math. Soc. (1999) 137
[24] , Homology cylinders: an enlargement of the mapping class group, Algebr. Geom. Topol. 1 (2001) 243
[25] , The Lagrangian filtration of the mapping class group and finite-type invariants of homology spheres, Math. Proc. Cambridge Philos. Soc. 141 (2006) 303
[26] , Introduction to algebraic K–theory, 72, Princeton Univ. Press (1971)
[27] , On the homology of Lie groups made discrete, Comment. Math. Helv. 58 (1983) 72
[28] , Characteristic classes of surface bundles, Invent. Math. 90 (1987) 551
[29] , The extension of Johnson’s homomorphism from the Torelli group to the mapping class group, Invent. Math. 111 (1993) 197
[30] , The Picard group of the moduli space of curves with level structures
[31] , Algebraic K–theory and its applications, 147, Springer (1994)
[32] , The Johnson homomorphism and the third rational cohomology group of the Torelli group, Topology Appl. 148 (2005) 83
[33] , The cohomology of SL3(Z), Topology 17 (1978) 1
[34] , The Schur multipliers of Sp6(Z), Spin8(Z), Spin7(Z), and F4(Z), Math. Ann. 215 (1975) 165
[35] , The Schur multipliers of SL(3,Z) and SL(4,Z), Math. Ann. 212 (1974/75) 47
Cité par Sources :