Optimal conditions for maximum and antimaximum principles of the periodic solution problem.
Further extension of the Levinson transformation theory is performed for partially dissipative periodic processes via the fixed point index. Thus, for example, the periodic problem for differential inclusions can be treated by means of the multivalued Poincaré translation operator. In a certain case, the well-known Ważewski principle can also be generalized in this way, because no transversality is required on the boundary.
Two theorems about period doubling bifurcations are proved. A special case, where one multiplier of the homogeneous solution is equal to +1 is discussed in the Appendix.
The paper deals with the periodic boundary value problem (1) , , (2) , , where , , , , , and are continuous on , , , , {nonempty convex compact subsets of }, . The existence of such periodic solution is proven via Ky Fan’s fixed point theorem.