3 problems

Let $n(x)$ be a refractive index and let the scattering amplitude be measured with a fixed incident direction $d\in\mathbb{S}^{N-1}$, as a function of the observation direction and…

Let $n_1$ and $n_2$ be refractive indices, with corresponding scattering amplitudes $u_\infty^1(\hat x;d,k)$ and $u_\infty^2(\hat x;d,k)$. A measurement set is formally determined…

Let $n_\star(x)$ be a locally optimal one-dimensional refractive index on the interval $[0,L]$, taking the values $n_+$ and $n_-=1$ on its material intervals. The point $x=L/2$ is…