Variational problems in phase transition systems centre on energy functionals that balance interfacial costs and bulk or nonlocal interactions to determine collective patterns of coexisting phases.

Ekeland’s variational principle serves as a fundamental tool in modern optimisation theory, offering a framework to identify approximate solutions under minimal assumptions. Its versatility has ...

For the past six years, Los Alamos National Laboratory has led the world in trying to understand one of the most frustrating barriers that faces variational quantum computing: the barren plateau.