activity
20082024
most citedA Critical Comparison of Lagrangian Methods for Coherent Structure Detection

221 citations · 1.5k across the 51 of their papers we have counts for

collaborators

56 papers

physics.flu-dyn2024

An inflated dynamic Laplacian to track the emergence and disappearance of semi-material coherent sets

Jason Atnip, Gary Froyland, Péter Koltai

Lagrangian methods continue to stand at the forefront of the analysis of time-dependent dynamical systems. Most Lagrangian methods have criteria that must be fulfilled by trajector…

math.DS2023

Universal Gap Growth for Lyapunov Exponents of Perturbed Matrix Products

Jason Atnip, Gary Froyland, Cecilia González-Tokman +1

We study the quantitative simplicity of the Lyapunov spectrum of -dimensional bounded matrix cocycles subjected to additive random perturbations. In dimensions 2 and 3, we estab…

math.DS2023★ 1 cited

Optimal linear response for expanding circle maps

Gary Froyland, Stefano Galatolo

We consider the problem of optimal linear response for deterministic expanding maps of the circle. To each infinitesimal perturbation of a circle map we consider (i)…

math.DS2023

A dynamic -Laplacian

Alvaro de Diego Unanue, Gary Froyland, Oliver Junge +1

We generalise the dynamic Laplacian introduced in (Froyland, 2015) to a dynamic -Laplacian, in analogy to the generalisation of the standard -Laplacian to the standard -La…

math.DS2023

Revealing trends and persistent cycles of non-autonomous systems with operator-theoretic techniques: Applications to past and present climate dynamics

Gary Froyland, Dimitrios Giannakis, Edoardo Luna +1

An important problem in modern applied science is characterizing the behavior of systems with complex internal dynamics subjected to external forcings from their environment. While…

math.DS2023★ 1 cited

Compound Poisson statistics for dynamical systems via spectral perturbation

Jason Atnip, Gary Froyland, Cecilia González-Tokman +1

We consider random transformations where each map acts on a complete metrizable space . The randomness comes from an…

math.DG2023★ 3 cited

Higher Cheeger ratios of features in Laplace-Beltrami eigenfunctions

Gary Froyland, Christopher P. Rock

This paper investigates links between the eigenvalues and eigenfunctions of the Laplace-Beltrami operator, and the higher Cheeger constants of smooth Riemannian manifolds, possibly…

math.DS2023

Thermodynamic Formalism and Perturbation Formulae for Quenched Random Open Dynamical Systems

Jason Atnip, Gary Froyland, Cecilia Gonzalez-Tokman +1

We develop a quenched thermodynamic formalism for open random dynamical systems generated by finitely branched, piecewise-monotone mappings of the interval. The openness refers to…

physics.ao-ph2023

Bathymetry imposes a global pattern of cross-front transport in the Southern Ocean

Michael C Denes, Shane R Keating, Gary Froyland

The Southern Ocean plays an integral role in the global climate system, exchanging heat, salt, and carbon throughout the major ocean basins via the deep, fast-flowing Antarctic Cir…

math.DS2022

Perturbation formulae for quenched random dynamics with applications to open systems and extreme value theory

Jason Atnip, Gary Froyland, Cecilia Gonzalez-Tokman +1

We consider quasi-compact linear operator cocycles driven by an invertible ergodic pr…

physics.flu-dyn2021

Persistence and material coherence of a mesoscale ocean eddy

Michael C. Denes, Gary Froyland, Shane R. Keating

Ocean eddies play an important role in the transport and mixing processes of the ocean due to their ability to transport material, heat, salt, and other tracers across large distan…

math.DS2021★ 6 cited

Deep Lagrangian connectivity in the global ocean inferred from Argo floats

Ryan Abernathey, Christopher Bladwell, Gary Froyland +1

We describe the application of a new technique from nonlinear dynamical systems to infer the Lagrangian connectivity of the deep global ocean. We approximate the dynamic Laplacian…

math.DS2021★ 8 cited

Equilibrium states for non-transitive random open and closed dynamical systems

Jason Atnip, Gary Froyland, Cecilia González-Tokman +1

We prove a random Ruelle--Perron--Frobenius theorem and the existence of relative equilibrium states for a class of random open and closed interval maps, without imposing transitiv…

physics.ao-ph2021★ 46 cited

Spectral analysis of climate dynamics with operator-theoretic approaches

Gary Froyland, Dimitrios Giannakis, Benjamin Lintner +2

The Earth's climate system is a classical example of a multiscale, multiphysics dynamical system with an extremely large number of active degrees of freedom, exhibiting variability…

math.DS2021★ 1 cited

Thermodynamic Formalism for Random Interval Maps with Holes

Jason Atnip, Gary Froyland, Cecilia González-Tokman +1

We develop a quenched thermodynamic formalism for open random dynamical systems generated by finitely branched, piecewise-monotone mappings of the interval. The openness refers to…

math.DS2021★ 18 cited

Detecting the birth and death of finite-time coherent sets

Gary Froyland, Péter Koltai

Finite-time coherent sets (FTCSs) are distinguished regions of phase space that resist mixing with the surrounding space for some finite period of time; physical manifestations inc…

math.DS2021★ 18 cited

Optimal linear response for Markov Hilbert-Schmidt integral operators and stochastic dynamical systems

Fadi Antown, Gary Froyland, Stefano Galatolo

We consider optimal control problems for discrete-time random dynamical systems, finding unique perturbations that provoke maximal responses of statistical properties of the system…

math.DS2020★ 4 cited

Angular values of nonautonomous and random linear dynamical systems: Part I -- Fundamentals

Wolf-Jürgen Beyn, Gary Froyland, Thorsten Hüls

We introduce the notion of angular values for deterministic linear difference equations and random linear cocycles. We measure the principal angles between subspaces of fixed dimen…

math.DS2020★ 13 cited

Thermodynamic Formalism for Random Weighted Covering Systems

Jason Atnip, Gary Froyland, Cecilia González-Tokman +1

We develop a quenched thermodynamic formalism for random dynamical systems generated by countably branched, piecewise-monotone mappings of the interval that satisfy a random coveri…

math.DS2019

Linear response for the dynamic Laplacian and finite-time coherent sets

Fadi Antown, Gary Froyland, Oliver Junge

Finite-time coherent sets represent minimally mixing objects in general nonlinear dynamics, and are spatially mobile features that are the most predictable in the medium term. When…

math.DS2019

Higher-Order Finite Element Approximation of the Dynamic Laplacian

Nathanael Schilling, Gary Froyland, Oliver Junge

The dynamic Laplace operator arises from extending problems of isoperimetry from fixed manifolds to manifolds evolved by general nonlinear dynamics. Eigenfunctions of this operator…

math.DS2019★ 19 cited

Fourier approximation of the statistical properties of Anosov maps on tori

Harry Crimmins, Gary Froyland

We study the stability of statistical properties of Anosov maps on tori by examining the stability of the spectrum of an analytically twisted Perron-Frobenius operator on the aniso…

math.DS2019

Computation and optimal perturbation of finite-time coherent sets for aperiodic flows without trajectory integration

Gary Froyland, Péter Koltai, Martin Stahn

Understanding the macroscopic behavior of dynamical systems is an important tool to unravel transport mechanisms in complex flows. A decomposition of the state space into coherent…

math.DS2018

A spectral approach for quenched limit theorems for random hyperbolic dynamical systems

D. Dragičević, G. Froyland, C. González-Tokman +1

We extend the recent spectral approach for quenched limit theorems developed for piecewise expanding dynamics under general random driving [DrFrGTVa18] to quenched random piecewise…