Resumen de Aproximation by invertible elements and the generalized E-stable rank for A(D)R and C(D)sym
We determine the generalized E-stable ranks for the real algebra, C(D)sym, of all complex valued continuous functions on the closed unit disk, symmetric to the real axis, and its subalgebra A(D)R of holomorphic functions. A characterization of those invertible functions in C(E) is given that can be uniformly approximated on E by invertibles in A(D)R. Finally, we compute the Bass and topological stable rank of C(K)sym for real symmetric compact planar sets K.
