2 problems

For each fixed integer $n$, let $R_{p,n+1}$ be the quadric hypersurface ring of dimension $n+1$ in characteristic $p$, and let ${\bf m}$ be its homogeneous maximal ideal. Yoshida's…

Let $X$ be a general quadric hypersurface, and let $M$ be an analytic submanifold of $X$ that is not included in an isotropic subspace. Here, $M$ is extremal if it has the extremal…