Geometry of divisors

Nef line bundle

In algebraic geometry, a line bundle on a projective variety is nef if it has nonnegative degree on every curve in the variety. The classes of nef line bundles are described by a convex cone, and the possible contractions of the variety correspond to certain faces of the nef cone. In view of the correspondence between line bundles and divisors (built from codimension-1 subvarieties), there is an equivalent notion of a nef divisor. (Wikipedia).

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From playlist Misc

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Related pages

Abelian variety | Complex differential form | Irreducible component | Proj construction | Vector space | Torsion (algebra) | Convex cone | Néron–Severi group | Tensor product of modules | Ample line bundle | Pullback bundle | Projective variety | Genus (mathematics) | Adequate equivalence relation | Invertible sheaf | Cone of curves | Abundance conjecture | Characteristic (algebra) | Connected space | Jean-Pierre Demailly | Dual space | Field (mathematics) | Jacobian variety | Contraction morphism | Proper morphism | Intersection number | Algebraic geometry | Real number | Codimension | Picard group | Blowing up | Linear combination | Ruled surface | Divisor (algebraic geometry) | Scheme (mathematics) | Algebraic curve | Algebraic group | Line bundle | Normal scheme | Smoothness