Abstract
The previous results can only guarantee the existence of weak solutions, i.e., in the case of m = 1 only first derivatives in \(L^2(\it\Omega)\) can be proven. In the beginning we also asked for second derivatives satisfying the equation \(\mathcal{O}(h^k)\) requires a solution in \(H^{1+k}(\it\Omega)\). Therefore the crucial question is, under what conditions the weak solution also belongs to Sobolev spaces of higher order (cf. Section 9.1). Section 9.2 characterises a specific property of elliptic solutions: In the interior of the domain the solution is smoother than close to the boundary. In the case of analytic coefficients the solution is also analytic in the interior and the bounds of the (higher) derivatives improve with the distance from the boundary. This behaviour also holds for the singularity and Green’s function. In Section 9.3 the regularity properties of solutions of difference schemes is studied. When comparing the error estimates for difference methods in §4.5 with those for finite-element estimates in §8.5 one observes that the latter require much weaker smoothness of the solution. However, one gets similar estimate for difference methods if one uses suitable discrete regularity properties (cf. §9.3.3). Unfortunately, the proof of these properties is rather technical, much more involved, and inflexible compared with the finite-element case.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Author information
Authors and Affiliations
Rights and permissions
Copyright information
© 2017 Springer-Verlag GmbH Germany
About this chapter
Cite this chapter
Hackbusch, W. (2017). Regularity. In: Elliptic Differential Equations. Springer Series in Computational Mathematics, vol 18. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-54961-2_9
Download citation
DOI: https://doi.org/10.1007/978-3-662-54961-2_9
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-662-54960-5
Online ISBN: 978-3-662-54961-2
eBook Packages: Mathematics and StatisticsMathematics and Statistics (R0)