Matlab Experiments on Extrapolation of The Nonconforming Crouzeix-Raviart Element for Steklov Eigenvalue Problem

Since the regulartiy of eigenfunction of Steklov eigenvalue problem is rather low, it brings great difficulty in studying the asymptotic expansion of Crouzeix-Raviart element eigenvalues. This paper explores the extrapolation rules of the nonconforming Crouzeix-Raviart element for Steklov eigenvalue problem by numerical experiments of Mat lab programs. Numerical results show that the asymptotic expansion for numerical eigenvalues holds and the accuracy order of the approximate eigenvalue is improved by using the extrapolation.