Computing Ext for toric divisors - MathOverflow most recent 30 from http://mathoverflow.net 2013-05-20T07:33:27Z http://mathoverflow.net/feeds/question/73029 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/73029/computing-ext-for-toric-divisors Computing Ext for toric divisors Karl Schwede 2011-08-17T03:23:05Z 2011-08-17T20:06:50Z <p>Ok, I have an affine (normal) toric variety $X = \text{Spec} k[\sigma]$. Suppose that $F, G$ are two torus invariant Weil divisors on $X$. Is there any relatively straightforward way to compute $$\text{Ext}^i_{\mathcal{O}_X}(\mathcal{O}_X(F), \mathcal{O}_X(G))?$$ If it helps, I'm happy to assume that $F$ and $G$ are effective (one can twist to that case up to isomorphism anyways), but obviously I can't assume that $F$ is Cartier...</p> <p>I'd be particularly interested in doing this if $X$ is dimension 3. Even (and perhaps especially for) specific examples.</p>