2 problems

Let $N\geq 7$, let $\mathbb S_N^+$ be the Spinor variety, let $\sigma_2(\mathbb S_N^+)$ be its secant variety of lines, and let $\Sigma_{2,N}$ be the distance--$2$ orbit. The singu…

Let $\mathcal{M}=(G,In,Out,Leak)$ be a linear compartment model with input, output, and leak in compartment $1$ only, so that $In=Out=Leak=\{1\}$, and suppose that $G$ is a bidirec…