TY - JOUR T1 - A Note on Optimal Spectral Bounds for Nonoverlapping Domain Decomposition Preconditioners for $hp$-Version Discontinuous Galerkin Methods JO - International Journal of Numerical Analysis and Modeling VL - 4 SP - 513 EP - 524 PY - 2016 DA - 2016/07 SN - 13 DO - http://doi.org/ UR - https://global-sci.org/intro/article_detail/ijnam/450.html KW - Schwarz preconditioners, $hp$-discontinuous Galerkin methods. AB -

In this article, we consider the derivation of $hp$-optimal spectral bounds for a class of domain decomposition preconditioners based on the Schwarz framework for discontinuous Galerkin finite element approximations of second-order elliptic partial differential equations. In particular, we improve the bounds derived in our earlier article [P.F. Antonietti and P. Houston, J. Sci. Comput., 46(1):124-149, 2011] in the sense that the resulting bound on the condition number of the preconditioned system is not only explicit with respect to the coarse and fine mesh sizes $H$ and $h$, respectively, and the fine mesh polynomial degree $p$, but now also explicit with respect to the polynomial degree $q$ employed for the coarse grid solver. More precisely, we show that the resulting spectral bounds are of order $p^{2}H/(qh)$ for the $hp$-version of the discontinuous Galerkin method.