Eigenvalues of Robin Laplacians in infinite sectors

Magda Khalile, Konstantin Pankrashkin

For $\alpha \in (0,\pi )$, let $U_{\alpha }$ denote the infinite planar sector of opening $2\alpha$, \[ U_α=\big\{ (x_1,x_2)\in\mathbb R^2: \big|\arg(x_1+ix_2) \big|<α\big\}, \] and $T_{\alpha }^{\gamma }$ be the Laplac…