Lifting sections of bundles - MathOverflow most recent 30 from http://mathoverflow.net 2013-05-20T08:32:16Z http://mathoverflow.net/feeds/question/6799 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/6799/lifting-sections-of-bundles Lifting sections of bundles Timo Schürg 2009-11-25T12:49:45Z 2009-12-22T05:30:18Z <p>Assume that $X$ is a quasiprojective scheme with a fixed imbedding into a smooth scheme M given by an ideal sheaf $\mathcal{I}$. Assume further that there is a locally free sheaf $E_X$ on $X$ that is a restriction of a sheaf $E_M$ on $M$. The last piece of data is a surjective morphism $f:E_M\to \mathcal{I}/\mathcal{I}^2$.</p> <p>Locally it is always possible to lift $f$ to a morphism from $E_M$ to $I$, which both are sheaves on $M$, not $X$ anymore. Does anybody happen to know whether this also possible globally?</p> <p>Feel free to modify $M$ as much as you want. Actually I would be happy if i could find one specific $M$ such that the locally free sheaf on $X$ is a restriction and the morphism to the conormal sheaf lifts. The only thing that is fixed is $X$. What is also important to me is that I can not assume $X$ to be a locally complete intersection, it can be arbitrarily bad. So $\mathcal{I}/\mathcal{I}^2$ will in general only be a cone, not a bundle. </p>