Georgia Institute of Technology College of Sciences

We discuss the proof of the following Theorem

Assume $E$ is a $C^{p}$ real Banach manifold, and $f:E\circlearrowleft$, $f\circ f=f$ is a $C^{p}$ retraction, where $1\leq p\leq +\infty$. Then the retract $f(E)$ is a $C^{p}$ sub Banach manifold of $E$.

If time allows, we will also discuss how this fact is related to the study of smoothness and structural stability of attractors, along the intersection of topology and dynamics. We will be focusing on the proof and perspective of Oliva 1975, who was interested in Banach manifolds as phase-spaces of delay equations.