nef meaning: definition, etymology and quotations

nef

noun

/nɛf/

Etymology Borrowed from French nef. Doublet of nave and nau.

An extravagant table ornament and container used in the Middle Ages and Renaissance, made in the shape of a ship.

Related terms: cadenas, navicula

nef

adj

Etymology Short for numerically effective; introduced by Miles Reid.

Algebraic geometry, Geometry, Mathematics, Sciences Of a line bundle on a complete algebraic variety over a field: such that the degree of its restriction to every algebraic curve in the variety is non-negative.

[…] this condition is the numerical consequence of the condition that for some mgt;0, the linear system #124;mD#124; is effective and free; thus nef = "numerically (effective and free)".1983, Miles Reid, “Minimal Models of Canonical 3-Folds”, in Advanced Studies in Pure Mathematics, volume 1, page 131:

Derived terms: nefness