Abstract:
In this paper, we construct, for each $n\in\mathbb N$, a compact set $X\subset\mathbb C$ (depending on $n$) such that the set of all polyanalytic polynomials of order $n$ is not dense in $\mathrm C(X)$, but the set of all polyanalytic polynomials of order $2n$ is already dense in $\mathrm C(X)$.