| ¡@¡@The Zienkiewicz-Zhu path recovery is a post-processing technique for the finite element method. It recovers gradient quantities in an element from element patches surrounding the nodes of the element. It has been shown numerically that ZZ provides superconvergent recovery on regular meshes and provides recovery with much improved accuracy on general meshes. In this talk, we present a theoretical investigation on this remarkable recovery technique and prove its superconvergence under rectangular grids. |