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20122026
most citedThe index bundle for Fredholm morphisms

13 citations · 14 across the 13 of their papers we have counts for

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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.FA2023

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…

math.FA2021

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…

math.FA2020

The Index Bundle for Selfadjoint Fredholm Operators and Multiparameter Bifurcation for Hamiltonian Systems

Robert Skiba, Nils Waterstraat

The index of a selfadjoint Fredholm operator is zero by the well-known fact that the kernel of a selfadjoint operator is perpendicular to its range. The Fredholm index was generali…

math.FA2020

Fredholm theory of families of discrete dynamical systems and its applications to bifurcation theory

Robert Skiba, Nils Waterstraat

In a previous work, we proved an index theorem for families of asymptotically hyperbolic discrete dynamical systems and obtained applications to bifurcation theory. A weaker and fa…

math.FA2019

On a Comparison Principle and the Uniqueness of Spectral Flow

Maciej Starostka, Nils Waterstraat

The spectral flow is a well-known quantity in spectral theory that measures the variation of spectra about along paths of selfadjoint Fredholm operators. The aim of this work i…