A posteriori error analysis for unstable models.

In this paper, we consider the possibility of a posteriori error estimates for linear and nonlinear ill-posed operator equations. Given an auxiliary finite-dimensional problem , that approximates the original infinite model , with a certain level of accuracy, we try to estimate the distance between z, an approximate solution to , and , the exact solution to . The problem is assumed to accumulate different sources of error (discretization, measurements, etc.), and the computed solution z is assumed to satisfy the equation within a nonzero tolerance . We conduct both a theoretical and numerical study of a posteriori error analysis. [ABSTRACT FROM AUTHOR]