# isoperimetric problems on Alexandrov spaces

For an Alexandrov space M with curvature bounded from below, the isoperimetric profile $v \to I_M(v)$ defined for every $v\in (0,V(M))$ (the volume of M might be infinite), is given by $$I_M(v)=inf\{A(\partial D): V(D)=v, D \subset \subset M\},$$ where D varies over relatively compact open subset of M.

Then given any $v\in (0,V(M))$, is there a subset D with $A(\partial D)=I_M(v)$?

And are there any discription and regularity theorem for D and $\partial D$?

If we haven't results for general n, then what about the two-dimensional case?