Superconvergent Two-grid Methods For Elliptic Eigenvalue Problems
  Some numerical algorithms for elliptic eigenvalue problems are proposed, analyzed, and numerically tested. The methods combine advantages of the two-grid algorithm, two-space method, the shifted inverse power method, and the polynomial preserving recovery technique . Our new algorithms compare favorably with some existing methods and enjoy superconvergence property. 
Hailong Guo and Zhimin Zhang and Ren Zhao
math.NA