In this paper, we study the approximation of eigenvalues arising from the mixed Hellinger-Reissner elasticity problem by using a simple finite element introduced recently by one of the authors. We prove that the method converges when a residual type error estimator is considered and that the estimator decays optimally with respect to the number of degrees of freedom. A postprocessing technique originally proposed in a different context is discussed and tested numerically.
- adaptive finite elements
- eigenvalue problem
- Hellinger-Reissner elasticity