In algebraic geometry, a line bundle on an algebraic variety is said to be nef (short for "numerically effective" or "numerically eventually free"), if the degree of the restriction to any algebraic curve of the variety is non-negative.
In particular, every ample line bundle is nef.
Similarly, a Cartier divisor D on an algebraic variety X is nef, if
for any algebraic curve C in X, in the sense of intersection theory.
Famous quotes containing the words line and/or bundle:
“Gascoigne, Ben Jonson, Greville, Raleigh, Donne,
Poets who wrote great poems, one by one,
And spaced by many years, each line an act
Through which few labor, which no men retract.
This passion is the scholar’s heritage,”
—Yvor Winters (1900–1968)
“We styled ourselves the Knights of the Umbrella and the Bundle; for, wherever we went ... the umbrella and the bundle went with us; for we wished to be ready to digress at any moment. We made it our home nowhere in particular, but everywhere where our umbrella and bundle were.”
—Henry David Thoreau (1817–1862)