Weighted Energy-Dissipation principle for gradient flows in metric spaces

TL;DR

This paper introduces the Weighted Energy-Dissipation variational approach for analyzing gradient flows in metric spaces, providing a new approximation method and existence proof by minimizing a parameter-dependent functional.

Contribution

It develops a novel variational framework for gradient flows in metric spaces, offering a new existence proof and relaxation perspective through the WED approach.

Findings

Minimizers converge to curves of maximal slope as epsilon approaches zero.

The WED functional provides a new variational approximation for metric gradient flows.

The approach offers insights into relaxation and existence of solutions.

Abstract

This paper develops the so-called Weighted Energy-Dissipation (WED) variational approach for the analysis of gradient flows in metric spaces. This focuses on the minimization of the parameter-dependent global-in-time functional of trajectories \[ \mathcal{I}_\varepsilon[u] = \int_0^{\infty} e^{-t/\varepsilon}\left( \frac12 |u'|^2(t) + \frac1{\varepsilon}\phi(u(t)) \right) \dd t, \] featuring the weighted sum of energetic and dissipative terms. As the parameter $\varepsilon$ is sent to~$0$, the minimizers $u_\varepsilon$ of such functionals converge, up to subsequences, to curves of maximal slope driven by the functional $\phi$. This delivers a new and general variational approximation procedure, hence a new existence proof, for metric gradient flows. In addition, it provides a novel perspective towards relaxation.