Homomorphisms between algebras of $\mathcal F$-differentiable functions

T. Chaobankoh, J. F. Feinstein, S. Morley

Published 2015-11-30Version 1

Let $X$ be a perfect, compact subset of the complex plane, and let $D^{(1)}(X)$ denote the (complex) algebra of continuously complex-differentiable functions on $X$. Then $D^{(1)}(X)$ is a normed algebra of functions but, in some cases, fails to be a Banach function algebra. Bland and the second author investigated the completion of the algebra $D^{(1)}(X)$, for certain sets $X$ and collections $\mathcal{F}$ of paths in $X$, by considering $\mathcal{F}$-differentiable functions on $X$. In this paper, we investigate composition, the chain rule, and the quotient rule for this notion of differentiability. We also investigate homomorphisms between certain algebras of $\mathcal{F}$-differentiable functions.