User clemens koppensteiner - MathOverflow most recent 30 from http://mathoverflow.net 2013-05-21T01:42:45Z http://mathoverflow.net/feeds/user/459 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/126532/vanishing-of-restriction-of-constructible-sheaves Vanishing of !-restriction of constructible sheaves Clemens Koppensteiner 2013-04-04T15:56:22Z 2013-04-30T19:07:05Z <p>If $\mathcal F$ is a constructible sheaf (say of $\mathbb C$-modules) on a (real) manifold concentrated in degree $0$ and $i\colon Z \hookrightarrow X$ is a submanifold, can I say anything about $H^j(i^!\mathcal F)$ for $j > \operatorname{codim}_X Z$? Specifically, if $\mathcal F$ is constructible on $\mathbb R^n$ and $i$ is the embedding $\mathbb R^{n-1} \hookrightarrow \mathbb R^n$, does $H^j(i^! \mathcal F)$ vanish for $j > 1$?</p> <p>(The analoguous statement for coherent sheaves is: if $\mathcal{F}$ is a coherent sheaf on a variety and $Z$ is an l.c.i. subvarity of codimension $n$, then $H^i_Z(\mathcal F)$ vanishes for $i > n$.)</p> http://mathoverflow.net/questions/87613/what-does-the-t-in-t-category-stand-for What does the t in t-category stand for? Clemens Koppensteiner 2012-02-05T20:36:24Z 2012-02-05T23:55:32Z <p>To my knowledge the notion of a t-category was first introduced Beilinson, Bernstein and Deligne's Faiseaux Pervers. But while they explain the name "perverse sheaf", they don't give any indication how they came up with the name t-category.</p> <p>Does anyone know whether the "t" in "t-category"/"t-structure" stands for something specific?</p> http://mathoverflow.net/questions/761/undergraduate-level-math-books/795#795 Answer by Clemens Koppensteiner for Undergraduate Level Math Books Clemens Koppensteiner 2009-10-16T20:23:51Z 2009-10-16T20:23:51Z <p>Not exactly one of the topics in the question, but I particularly liked Silverman and Tate's <em>Rational Points on Elliptic Curves</em>.</p> http://mathoverflow.net/questions/126532/vanishing-of-restriction-of-constructible-sheaves Comment by Clemens Koppensteiner Clemens Koppensteiner 2013-04-04T15:57:01Z 2013-04-04T15:57:01Z (This was originally posted on math.SE, but didn't get any answers there: <a href="http://math.stackexchange.com/questions/339695/" rel="nofollow">math.stackexchange.com/questions/339695</a>)