Does "toric" conflict with "Calabi-Yau" in the projective case?

430 Views Asked by At

Let $X$ be a Calabi-Yau complex algebraic variety. If it is projective, we can talk about its geometric genus $p_g=h^{\dim X, 0}$, and the Calabi-Yau condition says that $p_g=1$.

Now, one might be interested in the so-called "local" Calabi-Yau varieties, which are not projective. Some of them are of greatest interest because they are toric. So my question is:

Q. Is it impossible for a smooth toric Calabi-Yau variety to be projective?

Put in another way: is the genus of a smooth projective toric variety always different from $1$?

Thank you for your time and your help!

1

There are 1 best solutions below

0
On BEST ANSWER

Yes, it is impossible. Toric varities are rational; a smooth projective rational variety has $p_g=0.$