Timeline for Torsion in cohomology

9 events

when toggle format	what		by	license	comment
Feb 25, 2015 at 5:39	comment	added	user53075		Ok, but if I understand correctly, this example does not satisfy that $H^i(C)$ is non zero for all $i$.
Feb 24, 2015 at 18:14	comment	added	Tyler Lawson		@user53075 You can shift Sasha's example up so that $A$ is concentrated in degree 2, $B$ is concentrated in degrees $1$ and $2$, and $C$ is concentrated in degree $1$.
Feb 24, 2015 at 11:42	history	edited	user53075	CC BY-SA 3.0	added 13 characters in body
Feb 24, 2015 at 11:41	comment	added	user53075		I am thinking of chain complexes with $A^k=0$, for $k<0$. Does this make any difference?
Feb 24, 2015 at 11:38	comment	added	Sasha		Add to $A$ and $C$ arbitrary acyclic complexes and to $B$ their direct sum.
Feb 24, 2015 at 11:37	comment	added	user53075		you are right, I forgot a couple of assumptions.
Feb 24, 2015 at 11:36	history	edited	user53075	CC BY-SA 3.0	added 59 characters in body
Feb 24, 2015 at 11:32	comment	added	Sasha		Of course not, take $A = Z$ (in degree 0), $B = Z \stackrel{2}\to Z$ (in degrees $-1$ and 0), $C = Z$ (in degree $-1$).
Feb 24, 2015 at 11:28	history	asked	user53075	CC BY-SA 3.0