Existence of weak solutions for two-phase matrix-valued harmonic map flows

TL;DR

This paper proves the existence of weak solutions for a specific two-phase matrix-valued harmonic map flow, using a novel time-discretization scheme, advancing understanding of such complex PDE systems.

Contribution

It introduces a modified minimizing movement scheme to establish weak solutions for matrix-valued two-phase harmonic map flows, linked to the Rubinstein-Sternberg-Keller problem.

Findings

Existence of weak solutions with optimal lifespan.

Development of a time-discretization approach for complex PDEs.

Connection to the Rubinstein-Sternberg-Keller problem.

Abstract

We investigate the existence of weak solutions for matrix-valued two-phase harmonic map flows with optimal lifespan, which arises as the limiting system of the matrix-valued Rubinstein-Sternberg-Keller problem studied by ({\em Invent. Math.}, 233(1):1--80, 2023). Our approach employs a modified minimizing movement scheme, discretizing the time domain and constructing approximate solutions by interpolating solutions to the associated functional problem within each small time interval.