A semiabelian variety is a connected algebraic group fitting into an exact
sequence
where
is an Abelian variety and
is a nonnegative integer.
This complex-field formulation describes an extension of
an Abelian variety by an algebraic
torus. For
it is an Abelian variety, and when
is a point it is a torus. The quasi-Albanese
variety is the universal semiabelian target for based algebraic maps from a smooth
quasi-projective variety.