Some observations concerning polynomial convexity

Abstract: In this paper we discuss a couple of observations related to polynomial convexity. More precisely, (i) We observe that the union of finitely many disjoint closed balls with centres in $\cup_{\theta\in[0,\pi/2]}e^{i\theta}V$ is polynomially convex, where $V$ is a Lagrangian subspace of $\mathbb{C}^n$. (ii) We show that any compact subset $K$ of ${(z,w)\in\mathbb{C}^2: q(w)=\overline{p(z)}}$, where $p$ and $q$ are two non-constant holomorphic polynomials in one variable, is polynomially convex and $\mathscr{P}(K)=\mathscr{C}(K)$.