21 research outputs found
A non-vanishing theorem for Q-divisors on surfaces
No full textWe prove a non-vanishing theorem of the cohomology H0 of the adjoint divisor KX + L where
L is the round up of a nef and big Q-divisor L
An optimal boundedness on weak Q-Fano 3-folds
No full textAbstractLet X be a terminal weak Q-Fano 3-fold. We prove that P−6(X)>0 and P−8(X)>1. We also prove that the anti-canonical volume has the universal lower bound −KX3⩾1/330. This lower bound is optimal
