Let R$R$ be a noetherian ring and M $M$ , N$N$ be finitely generated $R$-modules. Then what is the relation between $Ass Ext^i_R(M,N)$$Ass\ Ext^i_R(M,N)$ and $Ass M, Ass N$$Ass\ M, Ass\ N$?
$Ass$ means set of associated prime ideals.
It's well known that $Ass Hom_R(M,N) \subseteq Supp M \cap Ass N $$Ass\ Hom_R(M,N) \subseteq Supp\ M \cap Ass\ N $.