MathOverflow is a question and answer site for professional mathematicians. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Are there any complex surface or threefold $X$ with $$ \dim H^0(X,\Omega^{\dim_{\mathbb{C}} X})>2? $$ I am asking this because I don't know any example while there are complex curves of genus greater than one. I guess that there are no such example. If so, could someone kindly explain why? Any counter example is also welcome.

Edit My question turns out to be a silly question. Please ignore this.

share|cite|improve this question
Take $X=C_1×C_2$ where $C_1$ and $C_2$ are smooth curves. Then $h^0(X,K_X)=g(C_1)g(C_2)$ which can be as big as you wish – Francesco Polizzi Oct 11 '12 at 8:40
You are right. I think they belong to surfaces of general types and hence I am not familiar with and haven't seen them. – user2013 Oct 11 '12 at 8:55
Any abelian threefold also satisfies this. – J.C. Ottem Oct 11 '12 at 14:14
They are not necessarily surfaces of general type! – diverietti Oct 11 '12 at 14:22
Ok, ok. But as soon as $g(C_1)$ and $g(C_2)$ are at least $2$ they are :-) – Francesco Polizzi Oct 11 '12 at 14:45

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.