Conditions of sourcewise representability and power estimates of convergence rate in Tikhonov's scheme for solving ill-posed extremal problems

We investigate rate of convergence estimates for approximations generated by Tikhonov's scheme for solving ill-posed optimization problems with general smooth functionals in a Hilbert space. Sourcewise representability conditions necessary and sufficient for convergence of approximations at the power rate are established. Sufficient conditions are related to estimates of a discrepancy by the objective functional while necessary ones are formulated for estimates by the argument. The cases are specified where sufficient and necessary conditions coincide in the main.