Exceptional Loci on ${\bar{M}}_{0,n}$ and Hypergraph Curves

Abstract

We give a myriad of examples of extremal divisors, rigid curves, and birational morphisms with unexpected properties for the Grothendieck--Knudsen moduli space ${\bar{M}}_{0,n}$ 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.

39 pages

References in corpus (1)

• Luigi Cremona and cubic surfaces