Unstabilized Hybrid High-Order method for a class of degenerate convex minimization problems
arXiv:2011.15059 · doi:10.1137/20M1335625
Abstract
The relaxation in the calculus of variation motivates the numerical analysis of a class of degenerate convex minimization problems with non-strictly convex energy densities with some convexity control and two-sided -growth. The minimizers may be non-unique in the primal variable but lead to a unique stress . Examples include the p-Laplacian, an optimal design problem in topology optimization, and the convexified double-well problem. The approximation by hybrid high-order methods (HHO) utilizes a reconstruction of the gradients with piecewise Raviart-Thomas or BDM finite elements without stabilization on a regular triangulation into simplices. The application of this HHO method to the class of degenerate convex minimization problems allows for a unique conforming stress approximation . The main results are a~priori and a posteriori error estimates for the stress error in Lebesgue norms and a computable lower energy bound. Numerical benchmarks display higher convergence rates for higher polynomial degrees and include adaptive mesh-refining with the first superlinear convergence rates of guaranteed lower energy bounds.