Doklady Earth Sciences. Том 462. 2015. С. 484-486
We obtain a number of necessary and sufficient strong ellipticity conditions for a functional-differential equation containing, in its leading part, orthotropic contractions of the argument of the unknown function. We establish the unique solvability of the first boundary-value problem and the discreteness, semiboundedness, and sectorial structure of its spectrum. © 2015, Pleiades Publishing, Ltd.