零次Del Pezzo曲面上的直线

The Lines on the Del Pezzo Surface of Degree 0

9-n的del Pezzo曲面S和李代数E_(n)(0≤n≤8)密切相关.给出次数为0的del Pezzo曲面X_(9)上有无穷多条直线的一个证明,并证明仿射型Weyl群W(E_(8))可迁地作用在这些直线上.

It is known that the del Pezzo surface S of degree 9-n is closely related to the Lie algebra E_(n),for 0≤n≤8.We investigate the property of the exceptional lines on a del Pezzo surface X_(9)of degree 0,and prove that there are infinitely many such lines.We also prove that the Weyl group W(E_(8))acts on these lines transitively.