Please could you explain why for a smooth projective variety over $\mathbb{C}$ (or - if you prefer the analytic world - compact complex manifold) $T$ we have $H^1(\mathcal{O}_T)\simeq H^{0,1}(T)$ as in the bottom of page 13 in this set of notes:
http://www.cgtp.duke.edu/ITP99/morrison/cortona.pdf
Thank you very much.
This is a special case of Dolbeault's theorem.
(By the way, a compact complex manifold is not the same thing as a smooth projective variety. Not all compact complex manifolds are projective.)