On extensions of the Torelli map

Abstract

The divisors on ${\bar{M}}_g$ that arise as the pullbacks of ample divisors along any extension of the Torelli map to any toroidal compactification of $A_g$ form a 2-dimensional extremal face of the nef cone of ${\bar{M}}_g$, which is explicitly described.

10 pages, 1 figure

References in corpus (3)

• Log minimal model program for the moduli space of stable curves: The first flip
• Extending Torelli map to toroidal compactifications of Siegel space
• Conformal blocks divisors on ${\bar{M}}_{0,n}$ from $s{l}_2$