Applied Mathematics and Optimization, Vol.83, No.2, 833-848, 2021
Vectorial Variational Principles in L-infinity and Their Characterisation Through PDE Systems
We discuss two distinct minimality principles for general supremal first order functionals for maps and characterise them through solvability of associated second order PDE systems. Specifically, we consider Aronsson's standard notion of absolute minimisers and the concept of infinity-minimal maps introduced more recently by the second author. We prove that C-1 absolute minimisers characterise a divergence system with parameters probability measures and that C-2 infinity-minimal maps characterise Aronsson's PDE system. Since in the scalar case these different variational concepts coincide, it follows that the non-divergence Aronsson's equation has an equivalent divergence counterpart.
Keywords:Calculus of variations in L-infinity;L-infinity variational principle;Aronsson system;infinity-Laplacian;Absolute minimisers;infinity-minimal maps