3 papers
math.DS2025
A Comparison Principle for Bifurcation of Periodic Solutions of Hamiltonian Systems
Helene Cyris, Joanna Janczewska, Nils Waterstraat
We obtain novel criteria for the existence of local bifurcation for periodic solutions of Hamiltonian systems by a comparison principle of the spectral flow. Our method allows to f…
math.FA2025
On the Uniqueness of the -Equivariant Spectral Flow
Marek Izydorek, Joanna Janczewska, Maciej Starostka +1
The spectral flow is an integer-valued homotopy invariant for paths of selfadjoint Fredholm operators. Lesch as well as Pejsachowicz, Fitzpatrick and Ciriza independently showed th…
math.DS2024
Local and Global Bifurcation for Periodic Solutions of Hamiltonian Systems via Comparison Theory for the Spectral Flow
Joanna Janczewska, Maciej Starostka, Nils Waterstraat
We obtain local and global bifurcation for periodic solutions of Hamiltonian systems by using a new way to apply a comparison principle of the spectral flow that was originally int…