Exceptional Loci on M_0,n and Hypergraph Curves

2008/09/10 by Ana-Maria Castravet, Castravet, Ana-Maria, Jenia Tevelev +1
Mathematics · #14 #Algebraic Geometry (math.AG) #FOS: Mathematics #math.AG #msc:14

paper · pdf · doi:10.48550/arxiv.0809.1699

39 pages

arxiv created 2008/09/10 · arxiv updated 2009/12/01

Abstract

We give a myriad of examples of extremal divisors, rigid curves, and birational morphisms with unexpected properties for the Grothendieck--Knudsen moduli space M_0,n of stable rational curves. The basic tool is an isomorphism between M_0,n and the Brill--Noether locus of a very special reducible curve corresponding to a hypergraph.

Related

• Distinguishing Brill-Noether loci
• On the derived category of M_0,n
• Hyperkähler varieties as Brill-Noether loci on curves
• Extremal divisors on moduli spaces of rational curves with marked points
• Birational contractions of M_0,n and combinatorics of extremal assignments