Weighted norm least squares finite element method for Poisson equation in a polyhedral domain

This paper concerns Poisson equation in a polyhedral domain with corners and edges. We apply the least-squares finite element method to the reformulated first-order system of Poisson equation. To overcome the difficulties from boundary singularities, a weighted-norm technique is used to define the least-squares functional. The method prevents the loss of global accuracy. Numerical simulations are given to demonstrate the theoretical estimates.