Let $A,B$ be Banach algebras and $A\hat{\otimes}B$ be projective tensor product of them. Let $S$ be an ideal of $A\hat{\otimes}B$. Are there ideals $I$ of $A$ and $J$ of $B$ such that $S=I\hat{\otimes}J$?
Thanks
Let $A,B$ be Banach algebras and $A\hat{\otimes}B$ be projective tensor product of them. Let $S$ be an ideal of $A\hat{\otimes}B$. Are there ideals $I$ of $A$ and $J$ of $B$ such that $S=I\hat{\otimes}J$?
Thanks
I suppose that you mean closed ideals. Howver the result is not even true in the simplest non-trivial case, that of two dimensional algebras. This is most easily seen by dualising it to the obviously false claim that closed subsets of products are products of closed subsets.