On the projective normality of cyclic coverings over a rational surface
Lei Song
所有作者
Lei Song
文献摘要
Let S be a rational surface with dim∣−KS∣≥1 and let $\pi:
X\rightarrow SbearamifiedcycliccoveringfromanonruledsmoothsurfaceX.Weshowthatforanyintegerk\ge 3andampledivisorAonS$, the
adjoint divisor KX+kπ∗A is very ample and normally generated. Similar
result holds for minimal (possibly singular) coverings.