5 problems

Let $\mathcal{B}$ and $\mathcal{F}$ be families consisting respectively of points and pseudo-disks, or of pseudo-disks and points. For a positive integer $m$, let…

Let $\mathcal A$ be a pseudo-disk arrangement, and let its members be the objects to be colored. The dual pseudo-disk arrangement conjecture. The members of any pseudo-disk arrange…

Let $\mathcal A$ be a pseudo-disk arrangement, meaning a family of planar bodies whose boundaries are Jordan curves and such that the boundary of any member intersects the boundary…

Let $\mathcal F$ be a family of pseudo-disks in the plane, let $S$ be a finite set of points, and let $m$ be a positive integer. The three-color pseudo-disk conjecture. If…

Let $4\mathcal{F}={\mathcal{R}_1,\ldots,\mathcal{R}_n}$ be a family of pseudo-disks in the plane whose interiors are pairwise disjoint, and let $\mathcal{H}_{\mathcal{F}}$ be the h…