For $0<r<R$, I am wondering if a given function $f$ which is analytic on the 2D-annulus,
$$\{(z,w)\in \mathbb C^2 \;|\; r<|z|<R,\ r<|z|<R\},$$
can be decomposed as such: $f = f_1 + f_2$, where
- $f_1$ is analytic on the hyperdisk $\{|z|,|w|< R\}$, and
- $f_2$ is analytic on the hyperdisk-at-infinity, $\{|z|,|w|> r\}$.
I suspect the answer is no:
Naively, one would expect the Laurent series of $f$ to contain monomials like $(z,w)↦ z^aw^{-b}$ ($a$, $b$ positive), for example;
but I'm unsure how to characterise those functions which can or can't be decomposed like this.