Abstract
We show that the group cohomology of the diffeomorphisms of the disk with n punctures has the cohomology of the braid group of n strands as the summand. As an application of this method, we also prove that there is no cohomological obstruction to lifting the “standard” embedding \(\mathrm {Br}_{2g+2}\hookrightarrow \mathrm {Mod}_{g,2}\) to a group homomorphism between diffeomorphism groups.
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Notes
We borrowed this notation from [6].
For a topological group G acting on a topological space X, the homotopy quotient is denoted by \(X//G\) and is given by \(X\times _G \mathrm {E}G\) where \(\mathrm {E}G\) is a contractible space on which G acts freely.
References
Aramayona, J., Souto, J.: Rigidity phenomena in the mapping class group. Handb. Teichmüller Theor. VI, 131–165 (2016)
Birman, J.S., Hilden, H.M.: On isotopies of homeomorphisms of Riemann surfaces. Ann. Math. 97, 424–439 (1973). doi:10.2307/1970830
Burghelea, D., Lashof, R.: The homotopy type of the space of diffeomorphisms. I, II. Trans. Am. Math. Soc. 196, 1–36 (1974). (ibid. 196 (1974), 37–50)
Bott, R.: Lectures on characteristic classes and foliations. In: Lectures on Algebraic and Differential Topology. Lecture Notes in Mathematics, vol. 279, pp. 1–94. Springer, Berlin (1972)
Ellenberg, J.S., Venkatesh, A., Westerland, C.: Homological stability for Hurwitz spaces and the Cohen-Lenstra conjecture over function fields, ii. arXiv:1212.0923 (2012)
Fuks, D.B.: Quillenization and bordism. Functional analysis and its applications 8(1), 31–36 (1974)
Gorin, E.A., Lin, V.J.: Algebraic equations with continuous coefficients, and certain questions of the algebraic theory of braids. Mat. Sb. (N.S.) 78(120), 579–610 (1969)
Haefliger, A.: Homotopy and integrability. In: Manifolds-Amsterdam 1970, In: Kuiper, N.H. (ed.) Manifolds–Amsterdam 1970. Proceedings of the Nuffic Summer School on Manifolds Amsterdam, August 17–29, 1970. Lecture Notes in Mathematics, vol. 197, pp. 133–163. Springer, Berlin (1971)
Hatcher, A.E.: A proof of the Smale conjecture, \(\text{ Diff }(S^3)\simeq \) O(4). Ann. Math. 117(3), 553–607 (1983). doi:10.2307/2007035
Kerckhoff, S.P.: The Nielsen realization problem. Ann. Math. 117(2), 235–265 (1983). doi:10.2307/2007076
Mann, K.: Realizing maps of braid groups by surface diffeomorphisms. http://www.math.brown.edu/~mann/papers/Realization.pdf (2017). Accessed May 2017
Markovic, V.: Realization of the mapping class group by homeomorphisms. Invention. Math. 168(3), 523–566 (2007)
Mather, J.N.: On the homology of Haefliger’s classifying space. In: Differential topology, pp. 71–116. Springer, Berlin, Heidelberg (2010)
McDuff, D.: The homology of some groups of diffeomorphisms. Commentarii Mathematici Helvetici 55(1), 97–129 (1980)
McDuff, D.: Local homology of groups of volume-preserving diffeomorphisms. iii. In: Annales scientifiques de l’École Normale Supérieure, vol. 16, pp. 529–540. Société mathématique de France (1983)
Morita, S.: Characteristic classes of surface bundles. Invention. Math. 90(3), 551–577 (1987)
Nariman, S.: Homological stability and stable moduli of flat manifold bundles. Adv. Math. 320, 1227–1268 (2017)
Nariman, S.: Stable homology of surface diffeomorphism groups made discrete. Geom. Topol. 21(5), 3047–3092 (2017). doi:10.2140/gt.2017.21.3047
Nariman, S.: On powers of the Euler class for flat circle bundles. J. Topol. Anal. 1–6 (2016). doi:10.1142/S1793525318500061
Pittie, H.V.: Characteristic classes of foliations, pp. v+107. Pitman, London, San Francisco, Melbourne, California (1976)
Rasmussen, O.H.: Continuous variation of foliations in codimension two. Topology 19(4), 335–349 (1980)
Segal, G.: Configuration-spaces and iterated loop-spaces. Invention. Math. 21(3), 213–221 (1973)
Smale, S.: Diffeomorphisms of the \(2\)-sphere. Proc. Am. Math. Soc. 10, 621–626 (1959)
Song, Y., Tillmann, U.: Braids, mapping class groups, and categorical delooping. Mathematische Annalen 339(2), 377–393 (2007)
Segal, G., Tillmann, U.: Mapping configuration spaces to moduli spaces. In: Groups of diffeomorphisms, vol. 52 of Advanced studies in pure mathematics, pp 469–477. Mathematical Society of Japan, Tokyo (2008)
Salter, N., Tshishiku, B.: On the non-realizability of braid groups by diffeomorphisms. Bull. Lond. Math. Soc. 48(3), 457–471 (2016)
Thurston, W.: Foliations and groups of diffeomorphisms. Bull. Am. Math. Soc. 80(2), 304–307 (1974)
Thurston, W.P.: A generalization of the Reeb stability theorem. Topology 13(4), 347–352 (1974)
Thurston, W.: Realizing braid group by homeomorphism. https://mathoverflow.net/questions/55555/realizing-braid-group-by-homeomorphisms (2011). Accessed Feb 2011
Acknowledgements
I would like to thank Søren Galatius for his support and helpful discussions during this project. I would like to thank Kathryn Mann for introducing me to the realization problems and her interest in 1.6. I am indebted to Alexander Kupers for reading the first draft of this work. I also like to thank Jeremy Miller, Johannes Ebert, Ricardo Andrade and Jonathan Bowden for helpful discussions. Bena Tshishiku and Nick Salter provided me with an earlier draft of their paper for which I am very grateful. This project was partially supported by NSF grant DMS-1405001. Finally I would like thank the referee for his/her careful reading and many helpful suggestions.
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Nariman, S. Braid groups and discrete diffeomorphisms of the punctured disk. Math. Z. 288, 1255–1271 (2018). https://doi.org/10.1007/s00209-017-1933-9
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DOI: https://doi.org/10.1007/s00209-017-1933-9