Classification of $K$-type formulas for the Heisenberg ultrahyperbolic operator ${\square }_s$ for $\widetilde{SL}(3,\mathbb{R})$ and tridiagonal determinants for local Heun functions

Toshihisa Kubo, Bent Ørsted

The $K$-type formulas of the space of $K$-finite solutions to the Heisenberg ultrahyperbolic equation ${\square }_{s}f=0$ for the non-linear group $\widetilde{SL}(3,\mathbb{R})$ are cla…