User cristian gonzalez-aviles - MathOverflow most recent 30 from http://mathoverflow.net 2013-05-22T22:28:20Z http://mathoverflow.net/feeds/user/6221 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/71663/hochschild-serre-for-hypercohomology Hochschild-Serre for hypercohomology cristian gonzalez-aviles 2011-07-30T16:42:25Z 2011-07-31T01:44:39Z <p>I need either a proof or a good reference for the following plausible statement:</p> <p>Let $S$ be a scheme and let $C$ be a bounded complex of abelian sheaves on $S_{\rm{fppf}}$. Let $S^{\prime}\rightarrow S$ be a finite etale Galois cover of $S$ with Galois group $G$. Then there exists a hypercohomology Hochschild-Serre spectral sequence in flat (fppf) cohomology $$H^{r}(G,{\mathbb H}^{s}(S',C))\implies {\mathbb H}^{r+s}(S,C).$$ This spectral sequence has been used by B.Kahn and E.Peyre when $S$ is the spectrum of a field. When C is a 1-term complex (i.e., simply an abelian sheaf on $S_{\rm{fppf}}$), the sequence is explicitly stated in Milne's Etale Cohomology book (bottom of p.105). The only question is whether the hypercohomology case has been handled by someone somewhere. Thanks in advance!</p> http://mathoverflow.net/questions/25434/subgroups-of-a-n-for-n5 Subgroups of A_n for n>=5 cristian gonzalez-aviles 2010-05-20T22:50:04Z 2010-05-20T23:14:16Z <p>How do I prove that $A_n$ has no proper subgroup of index less than $n$ if $n\geq 5$?</p>