Abstract
In this note, we prove that the well known saturation assumption implies that piecewise polynomial interpolation and best approximation in finite element spaces behave in similar fashion. That is, the error in one can be used to estimate the error in the other. We further show that interpolation error can be used as an a posteriori error estimate that is both reliable and efficient.
Similar content being viewed by others
References
Bank, R.E., Xu, J., Zheng, B.: Superconvergent derivative recovery for Lagrange triangular elements of degree \(p\) on unstructured grids. SIAM J. Numer. Anal. 45, 2032–2046 (2007)
Dupont, T., Scott, R.: Polynomial approximation of functions in Sobolev spaces. Math. Comp. 34, 441–463 (1980)
Veeser, A.: Approximating gradients with continuous piecewise polynomial functions. (2014) arXiv:1402.3945
Verfürth, R.: A posteriori error estimation techniques for finite element methods. Oxford University Press, Oxford (2013)
Author information
Authors and Affiliations
Corresponding author
Additional information
Randolph E. Bank was supported by the Alexander von Humboldt Foundation through a Humboldt Research Award, and by the US National Science Foundation through award DMS-1318480.
Rights and permissions
About this article
Cite this article
Bank, R.E., Yserentant, H. A note on interpolation, best approximation, and the saturation property. Numer. Math. 131, 199–203 (2015). https://doi.org/10.1007/s00211-014-0687-0
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00211-014-0687-0