## Regularized approximation methods with perturbations for ill-posed operator equations

• We are concerned with a parameter choice strategy for the Tikhonov regularization $$(\tilde{A}+\alpha I)\tilde{x}$$ = T* $$\tilde{y}$$+ w where $$\tilde{A}$$ is a (not necessarily selfadjoint) approximation of T*T and T*$$\tilde y$$+ w is a perturbed form of the (not exactly computed) term T*y. We give conditions for convergence and optimal convergence rates.