User terry mahr - MathOverflow most recent 30 from http://mathoverflow.net 2013-05-22T06:19:55Z http://mathoverflow.net/feeds/user/4084 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/15741/common-computations-in-group-cohomology Common Computations in Group Cohomology Terry Mahr 2010-02-18T19:02:13Z 2010-02-25T03:18:08Z <p>Let G=A&#8906;B, where A and B are abelian, and of coprime order. It seems, from my computations (and correct me if I'm wrong), that Z<sup>1</sup>(C<sub>p</sub>,C<sub>q</sub>) is trivial, for p and q different primes. Meaning that the automorphisms of G, if A=C<sub>q</sub>, and B=C<sub>p</sub>, that preserve A, and preserve the cosets G/A, are all trivial. How far can we extend this? Would it be true in general that Z<sup>1</sup>(A,B) is trivial, with the above assumptions (that A and B are abelian and of coprime order)? If not, under what assumptions is it trivial? And when can we say about it if it's not trivial?</p> http://mathoverflow.net/questions/15741/common-computations-in-group-cohomology Comment by Terry Mahr Terry Mahr 2010-02-18T19:17:58Z 2010-02-18T19:17:58Z No, I mean twisted as well. Otherwise it would just be direct product.