Complex geodesics, their boundary regularity, and a Hardy--Littlewood-type lemma

We begin by giving an example of a smoothly bounded convex domain that has complex geodesics that do not extend continuously up to $\mathrm{\partial }\mathbb{D}$. This example suggests that continuity at the boundary of the complex geodesics of a convex domain $\mathrm{\Omega }⋐{\mathbb{C}}^n$, $n\ge 2$, is affected by the extent to which $\mathrm{\partial }\mathrm{\Omega }$ curves or bends at each boundary point. We provide a sufficient condition to this effect (on ${\mathcal{C}}^1$-smoothly bounded convex domains), which admits domains having boundary points at which the boundary is infinitely flat. Along the way, we establish a Hardy–Littlewood-type lemma that might be of independent interest.