ABSTRACT
In this paper, we introduce a reliable and efficient a posteriori error estimator for the approximation of an eigenvalue problem using Brezzi-Douglas-Marini finite element spaces of any order. According to the author's knowledge, it is the first time that an a posteriori error analysis for mixed approximation of an eigenvalue problem is developed. Indeed, other authors see Duran et al. in [1] used the equivalence between the mixed finite element method of Raviart-Thomas of the lowest order and the non-conforming piece-wise linear approximation of Crouzeix and Raviart.