7 papers
Bifurcation for a Class of Indefinite Elliptic Systems by Comparison Theory for the Spectral Flow via an Index Theorem
J. Janczewska, M. Möckel, N. Waterstraat
We consider families of strongly indefinite systems of elliptic PDE and investigate bifurcation from a trivial branch of solutions by using the spectral flow. The novelty in our ap…
The Equivariant Spectral Flow and Bifurcation for Functionals with Symmetries -- Part I
Marek Izydorek, Joanna Janczewska, Maciej Starostka +1
We consider bifurcation of critical points from a trivial branch for families of functionals that are invariant under the orthogonal action of a compact Lie group. Based on a recen…
The Equivariant Spectral Flow and Bifurcation of Periodic Solutions of Hamiltonian Systems
Marek Izydorek, Joanna Janczewska, Nils Waterstraat
We define a spectral flow for paths of selfadjoint Fredholm operators that are equivariant under the orthogonal action of a compact Lie group as an element of the representation ri…
On the existence of homoclinic type solutions of a class of inhomogenous second order Hamiltonian systems
Jakub Ciesielski, Joanna Janczewska, Nils Waterstraat
We show the existence of homoclinic type solutions of second order Hamiltonian systems with a potential satisfying a relaxed superquadratic growth condition and a forcing term that…
The Maslov Index and the Spectral Flow - revisited
Marek Izydorek, Joanna Janczewska, Nils Waterstraat
We give an elementary proof of a celebrated theorem of Cappell, Lee and Miller which relates the Maslov index of a pair of paths of Lagrangian subspaces to the spectral flow of an…
On the existence of homoclinic type solutions of inhomogenous Lagrangian systems
Jakub Ciesielski, Joanna Janczewska, Nils Waterstraat
We study the existence of homoclinic type solutions for second order Lagrangian systems of the type , where , $q\in\mathbb…