Abstract.
In the paper, we generalize the methods of studying periodic solutions of linear systems of ordinary differential equations to linear multiperiodic systems with a differentiation operator along the main diagonal of the space of independent variables based on the study of the characteristic systems of partial differential operator on a multidimensional cylindrical manifold. A point on this manifold with time coordinates moves along the helix of a circular cylindrical surface , which is a periodic characteristic of the diagonal differentiation operator. In conclusion, we established the conditions for the multiperiodicity of solutions of linear systems with such an operator; justified the criteria for the multiperiodicity of solutions of systems associated with the matrix of those systems; determined the connections between periodic solutions of homogeneous and inhomogeneous systems based on the concept of conjugate systems; and provided integral representations of multiperiodic solutions using the Green function.



