Calculus of Variations and Geometric Measure Theory

A. Garroni - M. Petrache - E. Spadaro

Clearing-out of dipoles for minimisers of 2-dimensional discrete energies with topological singularities

created by petrache1 on 06 Aug 2024

[BibTeX]

preprint

Inserted: 6 aug 2024

Year: 2024

ArXiv: 2408.02136 PDF

Abstract:

A key question in the analysis of discrete models for material defects, such as vortices in spin systems and superconductors or isolated dislocations in metals, is whether information on boundary energy for a domain can be sufficient for controlling the number of defects in the interior. We present a general combinatorial dipole-removal argument for a large class of discrete models including XY systems and screw dislocation models, allowing to prove sharp conditions under which controlled flux and boundary energy guarantee to have minimizers with zero or one charges in the interior. The argument uses the max-flow min-cut theorem in combination with an ad-hoc duality for planar graphs, and is robust with respect to changes of the function defining the interaction energies.