We consider the solvability of boundary value problems and some inverse problems for operator-differential equations of odd order which can be referred to as mixed type equations since the coefficient of the higher order time derivative can change sign. Studying the general classes of boundary value problems with nonlocal boundary conditions, we establish the existence and uniqueness theorems of regular solutions under some conditions on data.

中文翻译：

---

一类非经典算子-微分方程的边值问题和逆问题

我们考虑了边值问题和奇数阶算子微分方程的一些逆问题的可解性，由于高阶时间导数的系数可以改变符号，因此可以称为混合型方程。研究具有非局部边界条件的边值问题的一般类，我们建立了数据在一定条件下正则解的存在唯一性定理。