The anticanonical bundle of a smooth variety or complex manifold 
is the dual 
of its canonical bundle 
. Its divisor class is the negative
of the canonical class. A smooth projective variety whose anticanonical bundle is
ample is called a Fano variety.
Anticanonical Bundle
See also
Canonical Bundle, Divisor, Line Bundle, Vector BundleExplore with Wolfram|Alpha
References
Hartshorne, R. Algebraic Geometry. New York: Springer-Verlag, 1977.Cite this as:
Weisstein, Eric W. "Anticanonical Bundle." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/AnticanonicalBundle.html