The purpose of this paper is to demonstrate the so-called Fredholm-inverse closedness of the Wiener algebra $W$ and to deduce independence of the Fredholm property and index of the underlying space. More precisely, we look at operators $A\in W$ as acting on a family of vector valued $\ell^p$ spaces and show that the Fredholm regularizer of $A$ for one of these spaces can always be chosen in $\W$ as well and therefore regularizes $A$ (modulo compact operators) on all of the $\ell^p$ spaces under consideration. We conclude that both Fredholmness and the index of $A$ do not depend on the $\ell^p$ space that $A$ is considered as acting on.
Keywords:
Fredholm operator, Fredholm index, Wiener algebra, operators on $\ell^p$ spaces.