Let $A$ be a commutative finite dimensional Frobenius algebra and $M$ a non-projective $A$-module.
Can we have $Ext_A^i(M,M)=0$ for some $i>0$?
Can we have $Ext_A^i(M,M)=0$ for some $i>0$ in case $A=kG$ is a group algebra?
Let $A$ be a commutative finite dimensional Frobenius algebra and $M$ a non-projective $A$-module.
Can we have $Ext_A^i(M,M)=0$ for some $i>0$?
Can we have $Ext_A^i(M,M)=0$ for some $i>0$ in case $A=kG$ is a group algebra?