Ashyralyev, Allaberen; Ashyralyyev, Charyyar

The boundary value problem of determining the parameter of an elliptic equation -u(t) + Au(t) = f(t) + p (0 ≤ t ≤ T), u(0) = φ, u(T) = ψ u(λ) = ξ 0 < λ < T, with a positive operator A in an arbitrary Banach space E is studied. The exact estimates are obtained for the solution of this problem in Hölder norms. Coercive stability estimates for the solution of boundary value problems for multi-dimensional elliptic equations are established.