Skip to main content
7 events
when toggle format what by license comment
Dec 24, 2017 at 6:36 comment added abx $\pi$ induces on each component a one-to-one map onto the (smooth) curve downstairs. That map is necessarily an isomorphism (think of the normalization).
Dec 24, 2017 at 6:29 comment added Feng Hao Sorry I have one more issue. Why have the two components to be smooth? , since it is branched covering.
Dec 24, 2017 at 6:15 history edited abx CC BY-SA 3.0
added 218 characters in body
Dec 24, 2017 at 6:13 comment added Feng Hao Sorry let me add my comments again: Thank you for your example Prof. Beauville. For the negative curve I always assume it is integral. I am not worrying about the geometric genus going to infinity, since I can prove that for surface of general type with ample canonical line bundle, there are only finitely many negative integral curves with geometric genus less than any given integer. I was worrying about that $C_i^2$ can be a fixed number. Are almost all the pullback curve $\pi^*E_n$ irreducibe in $X$? Thank you.
Dec 24, 2017 at 6:11 comment added abx It is not clear indeed, but I think it follows from the fact that $X$ contains only finitely many smooth rational curves (Lu-Miyaoka). If $\pi ^*E_n$ is not irreducible, it is the union of two smooth rational curves. I will edit my answer.
Dec 24, 2017 at 6:11 vote accept Feng Hao
Dec 24, 2017 at 5:24 history answered abx CC BY-SA 3.0