2 problems

Quadric-configuration conjecture. Every double $2d$ on $X$ consists of $4d$ lines that are the union of two quadric configurations on $X$.

Let $n\geq 3$ and consider timelike extremal cylinders, namely timelike extremal immersions of $\mathbb R\times\mathbb S^1$ into $(1+n)$-dimensional flat Minkowski space. Higher-di…