Nonvanishing and Abundance for cones of movable divisors

TL;DR

This paper introduces a generalized conjecture relating the positivity of certain divisor classes on projective varieties to their effective properties, extending key conjectures in algebraic geometry.

Contribution

It proposes a generalized version of the Log Nonvanishing and Log Abundance Conjectures for cones of movable divisors and proves their validity assuming the standard conjectures hold.

Findings

Proposes a generalized conjecture linking divisor classes and their effectivity.

Shows that the conjecture follows from the validity of the Log MMP, Nonvanishing, and Abundance.

Provides a framework connecting various fundamental conjectures in the minimal model program.

Abstract

Let $\overline{\mathrm{Mov}}^k(X)$ be the closure of the cone $\mathrm{Mov}^k(X)$ generated by classes of effective divisors on a projective variety $X$ with stable base locus of codimension at least $k+1$. We propose a generalized version of the Log Nonvanishing Conjecture and of the Log Abundance Conjecture for a klt pair $(X,\Delta)$, that is: if $K_X+\Delta \in \overline{\mathrm{Mov}}^{k}(X)$, then $K_X+\Delta \in \mathrm{Mov}^{k}(X)$. Moreover, we prove that if the Log Minimal Model Program, the Log Nonvanishing, and the Log Abundance hold, then so does our conjecture.