336 citations · 3.5k across the 72 of their papers we have counts for
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Objective Eulerian Coherent Structures
Mattia Serra, George Haller
We define objective Eulerian Coherent Structures (OECSs) in two-dimensional, non-autonomous dynamical systems as instantaneously most influential material curves. Specifically, OEC…
Dynamic Rotation and Stretch Tensors from a Dynamic Polar Decomposition
George Haller
The local rigid-body component of continuum deformation is typically characterized by the rotation tensor, obtained from the polar decomposition of the deformation gradient. Beyond…
Explicit form of spatially linear Navier-Stokes velocity fields
Gabriel Provencher Langlois, George Haller
We show that a smooth linear unsteady velocity field solves the incompressible Navier--Stokes equation if and only if the matrix has zero trace, and $\do…
Defining Coherent Vortices Objectively from the Vorticity
George Haller, Alireza Hadjighasem, Mohammad Farazmand +1
Rotationally coherent Lagrangian vortices are formed by tubes of deforming fluid elements that complete equal bulk material rotation relative to the mean rotation of the deforming…
A Spectral Clustering Approach to Lagrangian Vortex Detection
Alireza Hadjighasem, Daniel Karrasch, Hiroshi Teramoto +1
One of the ubiquitous features of real-life turbulent flows is the existence and persistence of coherent vortices. Here we show that such coherent vortices can be extracted as clus…
Polar rotation angle identifies elliptic islands in unsteady dynamical systems
Mohammad Farazmand, George Haller
We propose rotation inferred from the polar decomposition of the flow gradient as a diagnostic for elliptic (or vortex-type) invariant regions in non-autonomous dynamical systems.…