Extensions of toric line bundles

Abstract

For any two nef line bundles L+:=OX(Δ+) and L−:=OX(Δ−) on a toric variety X represented by lattice polyhedra Δ+ respectively Δ−, we present the universal equivariant extension of L− by L+ under use of the connected components of the set theoretic difference Δ−∖Δ+.