Abstract
Galerkin discretizations of integral operators in \(\mathbb {R}^{d}\) require an accurate numerical evaluation of integrals \(I={\int }_{\!\!S^{(1)}}{\int }_{\!\!S^{(2)}}f(x,y)dydx\) where S (1), S (2) are d-simplices and the integrand function f has a possibly nonintegrable singularity at x = y. In a previous paper (2011) we constructed several families of quadrature rules \({Q}_{\mathcal {N}}\) for a class of functions f which allow algebraic singularities at x = y, including hypersingular kernels, and are Gevrey smooth for x ≠ y. This holds for kernel functions commonly occurring in integral equations. In this paper we address the implementation aspects for computing \(Q_{\mathcal {N}}\) and give a detailed computation algorithm for arbitrary space dimension d and arbitrary mutual location of simplices S (1) and S (2). The algorithm consists of a “desingularizing” coordinate transformation, which reduces the singular support of the integrand to one variable while preserving Gevrey regularity in all 2d−1 remaining variables and simultaneously simplifies the integration domain to a unit cube. Due to the simple singularity structure after transformation, one can optionally use various combinations of quadrature rules in singular and regular directions. We report on comprehensive convergence studies for the full tensor product and Smolyak-type quadrature rules in the 2d−1 Gevrey-regular variables combined with either composite Gauss-Legendre or Gauss-Jacobi quadrature rules in the singular direction. A Matlab software implementing the algorithm complements this paper and is available from Netlib.
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Boutet de Monvel, L., Krée, P.: Pseudo-differential operators and Gevrey classes. Ann. Inst. Fourier (Grenoble) 17(fasc. 1), 295–323 (1967)
Chernov, A., von Petersdorff, T., Schwab, C.: Exponential convergence of hp quadrature for integral operators with Gevrey kernels. M2AN Math. Model. Numer. Anal. 45(3), 387–422 (2011)
Chernov, A., von Petersdorff, T., Schwab, C.: Netlib package na39, available at http://www.netlib.org/numeralgo
Chernov, A., Reinarz, A.: Numerical quadrature for high-dimensional singular integrals over parallelotopes. Comput. Math. Appl. 66(7), 1213–1231 (2013)
Chernov, A., Schwab, C.: Exponential convergence of Gauss-Jacobi quadratures for high dimensional singular integrands on simplices. SIAM J. Numer. Anal. 50(3), 1433–1455 (2012)
Costabel, M., Dauge, M., Nicaise, S.: Corner Singularities and Analytic Regularity for Linear Elliptic Systems. Part I: Smooth domains. HAL Archives http://hal.archives-ouvertes.fr/docs/00/45/41/17/PDF/CoDaNi_Analytic_Part_I.pdf (2010)
Gerstner, T., Griebel, M.: Numerical integration using sparse grids. Numer. Algorithms 18(3-4), 209–232 (1998)
Heiss, F., Winschel, V.: http://sparse-grids.de/
Heiss, F., Winschel, V.: Likelihood approximation by numerical integration on sparse grids. J. Econometrics 144(1), 62–80 (2008)
Hsiao, G.C., Wendland, W.L.: Strongly elliptic boundary integral equations, Springer Applied Mathematical Sciences Vol. 164. Springer Verlag (2008)
Krylov, V.I.: Approximate calculation of integrals, Translated by Arthur H. Stroud. The Macmillan Co., New York (1962)
Nédélec, J.-C.: Integral equations with nonintegrable kernels. Integr. Equ. Oper. Theory 5(4), 562–572 (1982)
Petras, K.: Smolyak cubature of given polynomial degree with few nodes for increasing dimension. Numer. Math. 93(4), 729–753 (2003)
Sauter, S., Schwab, C.: Boundary Element Methods. Springer Ser. Comput. Math. 39 (2010)
Schwab, C.: Variable order composite quadrature of singular and nearly singular integrals. Computing 53(2), 173–194 (1994)
Schwab, C.: p- and hp-finite element methods. The Clarendon Press Oxford University Press, New York (1998)
Schwab, C., Wendland, W.L.: Numerical Quadrature of Singular Surface Integrals in Boundary Element Methods. Numer. Math. 62, 343–369 (1992)
Stroud, A.H, Secrest, D.: Gaussian quadrature formulas, Prentice-Hall Inc., Englewood Cliffs. N.J (1966)
Trefethen, L.N.: Is Gauss quadrature better than Clenshaw-Curtis? SIAM Rev. 50(1), 67–87 (2008)
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A. Chernov acknowledges support by the HCM, University of Bonn and the University of Reading; C. Schwab was supported by ERC Advanced Grant AdG 247277.
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Chernov, A., von Petersdorff, T. & Schwab, C. Quadrature algorithms for high dimensional singular integrands on simplices. Numer Algor 70, 847–874 (2015). https://doi.org/10.1007/s11075-015-9977-6
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DOI: https://doi.org/10.1007/s11075-015-9977-6
Keywords
- Gauss-Jacobi quadrature
- Numerical integration
- High dimensional integrands
- Hypersingular integrals
- Integral equations
- Gevrey regularity
- Exponential convergence