Kummer subspaces of Central Simple Algebras

Let $F$ be a field containing a primitive $d^{th}$ root of unity $\rho$ and char$(F)\not|d$. Let $A$ be the tensor product of $n$ cyclic $F$-algebras. An element $v\in A$ is Kummer if $v^{d}\in F$. A subspace of $A$ is Kummer if every element is Kummer. Kummer spaces have been used to bound the symbol length of a central simple algebras. In this talk we will discuss some open problems concerning Kummer subspaces