Journal of Topology

Journal of Topology Advance Access originally published online on May 12, 2008
Journal of Topology 2008 1(3):527-550; doi:10.1112/jtopol/jtn006

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© 2008 London Mathematical Society

The structure and singularities of quotient arc complexes

R. C. Penner

Departments of Mathematics and Physics/Astronomy, University of Southern California, Los Angeles, CA 90089, USA
Center for the Topology and Quantization of Moduli Spaces, Department of Mathematics, Aarhus University, DK-8000 Aarhus C, Denmark rpenner@math.usc.edu

A well-known combinatorial fact is that the simplicial complex consisting of disjointly embedded chords in a convex planar polygon is a sphere. For any surface F with non-empty boundary, there is an analogous complex QA(F) consisting of equivalence classes of arcs in F connecting a given finite set of points in its boundary modulo diffeomorphisms of F pointwise fixing the boundary and any punctures. The main result of this paper is the determination of those complexes QA(F) that are also spheres. This classification has consequences for Riemann's moduli space of curves via its known identification with a related quotient arc complex in the punctured case with no boundary. Namely, the essential singularities of the natural cellular compactification of Riemann's moduli space can be described.

Received April 6, 2007.

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2000 Mathematics Subject Classification 32G15, 57M99 (primary)

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This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to My Personal Archive Download to citation manager Request Permissions Google Scholar Articles by Penner, R. C. Social Bookmarking          What's this?