Campana Rational Connectedness and Weak Approximation of Del Pezzo Orbifolds

Source abstract

We prove that a del Pezzo orbifold of degree less than 7, and del Pezzo orbifolds of higher degree with irreducible boundary are strongly Campana uniruled, and deduce that it is Campana rationally connected. This provides important non-toric examples in dimension two of a conjecture by Campana, in the form required by the weak approximation theorem, and yields weak approximation for Campana sections of Campana fibrations at all places whose general fibre is such an orbifold. In three appendices we classify the del Pezzo orbifolds of degree 6, 7 and 8 with irreducible boundary.