The pseudo-effective cone Eff(X) of a smooth projective variety X is a fundamental, yet elusive invariant. On one hand, a few general facts are known: the interior of the effective cone is the cone of big divisors so, in particular, X is of general type if and only if KX ∈ int(Eff(X)); less obviously [4], a variety X is uniruled if and only if KX is not pseudo-effective and the dual of Eff(X) i...
