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20212026
most citedThe regularized free fall I -- Index computations

5 citations · 5 across the 13 of their papers we have counts for

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math.SG2026

Towards a Floer theory for Mars II -- Floer Hessian field almost extends

Urs Frauenfelder, Joa Weber

In part I, \cite{Frauenfelder:2026c}, we showed that collisional periodic orbits of twisted Zeeman systems can be detected variationally by a non-local Hamiltonian action functiona…

math.SG2026

Towards a Floer theory for Mars I -- Twisted Zeeman systems

Urs Frauenfelder, Joa Weber

In this article we study periodic orbits of an electron attracted by a proton subject to Lorentz, electric, and Euler forces where each of them is allowed to depend periodically on…

math.SG2026

The kei word metric on the transvection group and its unit ball

Urs Frauenfelder, Lei Zhao

We define a bi-invariant word metric on a group using keis. We discuss whether such a word metric is trivial or non-trivial in various examples coming from group theory, dynamical…

math.SG2026

Merry-go-round and time-dependent symplectic forms

Urs Frauenfelder, Joa Weber

In the merry-go-round fictitious forces are acting like centrifugal force and Coriolis force. Like the Lorentz force Coriolis force is velocity dependent and, following Arnold, can…

math.SG2025

The Linearized Floer Equation in a Chart

Urs Frauenfelder, Joa Weber

In this article, we are considering the Hessian of the area functional in a non-Darboux chart. This does not seem to have been considered before and leads to an interesting new mat…

math.SG2025

Loop space blow-up and scale calculus

Urs Frauenfelder, Joa Weber

In this note we show that the Barutello-Ortega-Verzini regularization map is scale smooth.

math.SG2025

A variational approach to time-dependent planar two-center Stark-Zeeman systems

Urs Frauenfelder, Seongchan Kim

We study periodic orbits in a time-dependent two-center Stark-Zeeman system, which models the motion of a charged particle attracted by two fixed Coulomb centers and subject to ext…

math.SG2025

Hilbert manifold structures on path spaces

Urs Frauenfelder, Joa Weber

In Floer theory one has to deal with two-level manifolds like for instance the space of loops and the space of loops. Gradient flow lines in Floer theory are th…

math.SG2025

Periodic orbits in time-dependent planar Stark-Zeeman systems

Urs Frauenfelder

Time-dependent Stark-Zeeman systems describe the motion of an electron attracted by a proton subject to a magnetic and a time-dependent electric field. For instance the study of th…

math.SG2025

Floerfolds and Floer functions

Urs Frauenfelder, Joa Weber

In this article we introduce the notion of Floer function which has the property that the Hessian is a Fredholm operator of index zero in a scale of Hilbert spaces. Since the Hessi…

math.SG2024

On the spectral flow theorem of Robbin-Salamon for finite intervals

Urs Frauenfelder, Joa Weber

In this article we consider operators of the form where lies in an interval and is continuous. Without boundary conditions these op…

math.SG2024

Growth of eigenvalues of Floer Hessians

Urs Frauenfelder, Joa Weber

In this article we prove that the space of Floer Hessians has infinitely many connected components.

math.SG2024

Local gluing

Urs Frauenfelder, Joa Weber

In the local gluing one glues local neighborhoods around the critical point of the stable and unstable manifolds to gradient flow lines defined on a finite time interval f…

math.SG2021★ 5 cited

The regularized free fall I -- Index computations

Urs Frauenfelder, Joa Weber

Main results are, firstly, a generalization of the Conley-Zehnder index from ODEs to the delay equation at hand and, secondly, the equality of the Morse index and the clockwise nor…