6 problems

Terao's conjecture. Freeness is determined solely by the intersection lattice $\mathcal{L}$; equivalently, freeness is constant on $\mathcal{R}(\mathcal{L})$.

Let $C_{1}, C_{2}$ be reduced curves in $\mathbb{P}^{2}_{\mathbb{C}}$ whose irreducible components are smooth and whose singularities are ordinary quasi-homogeneous singularities.…

Let $G$ be a connected graph, and let ${\mathscr A}_G$ denote its connected subgraph arrangement. A free arrangement is flag-accurate if it is accurate and the tuple of flats witne…

Let $G$ be a connected graph, and let ${\mathscr A}_G$ denote its connected subgraph arrangement. An arrangement is inductively free if it belongs to the class of arrangements obta…

Let the arrangements be the arrangements between the extended Catalan arrangements $\operatorname{Cat}(\ell,m)$ and $\operatorname{Cat}(\ell,m-1)$ described by the gain-$m$ edges,…

Let $\mathcal{C}_{1},\mathcal{C}_{2} \subset \mathbb{P}^{2}_{\mathbb{C}}$ be two $d$-arrangements for a fixed $d\geqslant 1$. Let $G_{1}$ and $G_{2}$ be their associated Levi graph…