A linear dual-field finite element method for incompressible MHD, part I: cross-helicity and Alfv\'enic alignment in periodic domains
Cross helicity, together with total energy, determines the Els\"asser energies and thus quantifies departures from Alfv\'enic alignment in incompressible MHD. Building on the dual-field method in [Mao and Xi, \emph{J. Comput. Phys.}, 2025], we construct a linear finite element method for periodic domains that reproduce...