A posteriori error estimates of spectral method for nonlinear parabolic optimal control problem

J Inequal Appl. 2018;2018(1):138. doi: 10.1186/s13660-018-1729-4. Epub 2018 Jun 19.

Abstract

In this paper, we investigate the spectral approximation of optimal control problem governed by nonlinear parabolic equations. A spectral approximation scheme for the nonlinear parabolic optimal control problem is presented. We construct a fully discrete spectral approximation scheme by using the backward Euler scheme in time. Moreover, by using an orthogonal projection operator, we obtain L2(H1)-L2(L2) a posteriori error estimates of the approximation solutions for both the state and the control. Finally, by introducing two auxiliary equations, we also obtain L2(L2)-L2(L2) a posteriori error estimates of the approximation solutions for both the state and the control.

Keywords: A posteriori error estimates; Nonlinear parabolic equations; Optimal control problem; Spectral method; Variational discretization.