4 problems

Let $\mathbb{F}$ be either $\mathbb{R}$ or $\mathbb{C}$, and let $n$ nonidentical equi-isoclinic subspaces of dimension $r$ lie in a space of dimension $d$. For…

Let $d,N,k_1,\dots,k_N$ be positive integers and fix a spectral parameter $\boldsymbol{r}$. Let…

Let $N$, $r$, and $n$ be positive integers. Let $\Omega_1,\Omega_2,\cdots,\Omega_n$ be $n$ subsets of $r$ elements chosen uniformly at random from $\{1,\cdots,N\}$. Define … for…

Let $k$ denote the dimension of each block in the fusion frame model, and let $m$ be the number of measurements required for uniform recovery of fusion frame structured sparse sign…