Semiampleness criteria for divisors on ${\overline{M}}_{0,n}$

Abstract

We develop new characteristic-independent combinatorial criteria for semiampleness of divisors on ${\overline{M}}_{0,n}$. As an application, we associate to a cyclic rational quadratic form satisfying a certain balancedness condition an infinite sequence of semiample line bundles. We also give several sufficient and effective conditions for a symmetric divisor on ${\overline{M}}_{0,n}$ to be semiample or nef.

v1: 15 pages, 1 figure, 1 table, v2: major revision, includes new results and a streamlined proof of the main theorem of arXiv:1308.5993, 36 pages, 1 table

References in corpus (3)

• $s{l}_2$ conformal block divisors and the nef cone of ${\bar{M}}_{0,n}$
• Cyclic covering morphisms on ${\bar{M}}_{0,n}$
• On $S_n$-invariant conformal blocks vector bundles of rank one on ${\overline{M}}_{0,n}$