3 papers
math.AP2015
Periodic solutions for nonlinear evolution equations at resonance
Piotr Kokocki
We are concerned with periodic problems for nonlinear evolution equations at resonance of the form , where a densely defined linear operator $A\c…
math.DS2015
Krasnosel'skii type formula and translation along trajectories method for evolution equations
Aleksander Ćwiszewski, Piotr Kokocki
The Krasnosel'skii type degree formula for the equation where is a linear operator on a separable Banach space such that is a generato…
math.DS2015
Periodic solutions for nonlinear hyperbolic evolution systems
Piotr Kokocki, Aleksander Ćwiszewski
We shall deal with the periodic problem for nonlinear perturbations of abstract hyperbolic evolution equations generating an evolution system of contractions. We prove an averaging…