In this paper, we derive a posteriori error estimates for the finite element approximation of quadratic optimal boundary control problems. We derive a posteriori error estimates for both the state and the control approximation on polygonal domains. Such estimates, which are apparently not available in the literature, can be used to construct reliable adaptive finite element approximation schemes for the control problems. (C) 2000 Elsevier Science B.V. All rights reserved.
Liu, W., & Yan, N. (2000). A posteriori error estimates for some model boundary control problems. Journal of Computational and Applied Mathematics, 120(1–2), 159–173. https://doi.org/10.1016/S0377-0427(00)00308-3