Dr Stephen Langdon

• Department of Mathematics and Statistics
• University of Reading
• Whiteknights, PO Box 220
• Berkshire, RG6 6AX, UK

Email address: s.langdon@reading.ac.uk

Telephone: +44 (0)118 378 5021

Fax: +44 (0)118 931 3423

Ongoing research projects

• BEM++, an open source boundary element library.

• Boundary integral equation methods for high frequency scattering problems.

Recent and upcoming meetings

• Numerical Analysis Postgraduate Seminar Day, Friday March 30th 2012, University of Reading.

• Boundary Value Problems for Linear Elliptic and Integrable PDEs: Theory and Computation, May 28th-June 1st 2012, International Centre for Mathematical Sciences, Edinburgh.

• Eigenvalues/singular values and fast PDE algorithms: acceleration,conditioning, and stability, June 24th-29th 2012, Banff International Research Station for Mathematical Innovation and Discovery, Canada.

• Numerical Linear Algebra, Control Theory and Data Assimilation: a conference in honour of Nancy Nichols' 70th birthday, July 2nd-3rd 2012, University of Reading.

• MATHmONDES 2012, July 9th-10th 2012, University of Reading.

• Institute of Mathematics KickOff Meeting, July 17th-18th 2012, Hamburg University of Technology.

• Institute of Physics Tutorial Day on Numerical Modelling in Physical Acoustics, September 20th 2012, Institute of Physics, London.

• 15th IEEE International Conference on Computational Science and Engineering, December 5th-7th 2012, Paphos, Cyprus.

• Association for Science Education Annual Conference, January 2nd-5th 2013, University of Reading.

Publications

Recent preprints, submitted for publication

1. S. N. Chandler-Wilde, D. P. Hewett, S. Langdon and A. Twigger. A High Frequency Boundary Element Method for Scattering by a Class of Nonconvex Obstacles.
2. S. Langdon, D. J. Needham, B. A. Samson and J. P. Gilchrist. The unsteady flow of a weakly compressible fluid in a thin porous layer. III: Three-dimensional computations.
3. D. P. Hewett, S. Langdon and J. M. Melenk. A high frequency hp boundary element method for scattering by convex polygons.
4. D. J. Needham, S. Langdon, B. A. Samson and J. P. Gilchrist. The unsteady flow of a weakly compressible fluid in a thin porous layer. II: Three-dimensional theory.
5. T. E. Lee, M. J. Baines, S. Langdon and M. J. Tindall. A moving mesh approach for modelling avascular tumour growth.

Journal Publications (links are mostly to preprints)

6. S. N. Chandler-Wilde, I. G. Graham, S. Langdon and E. A. Spence. Numerical-asymptotic boundary integral methods in high frequency acoustic scattering. Acta Numerica, 21, 89-305, 2012.
7. S. N. Chandler-Wilde, S. Langdon and M. Mokgolele. A high frequency boundary element method for scattering by convex polygons with impedance boundary conditions. Communications in Computational Physics, 11(2), 573-593, February 2012.
8. T. Betcke, S. N. Chandler-Wilde, I. G. Graham, S. Langdon and M. Lindner. Condition number estimates for combined potential integral operators in acoustics and their boundary element discretisation. Numerical Methods for PDEs, 27(1), 31-69, January 2011.
9. S. Langdon, M. Mokgolele and S. N. Chandler-Wilde. High frequency scattering by convex curvilinear polygons. Journal of Computational and Applied Mathematics, 234, 2020-2026, (2010), doi: 10.1016/j.cam.2009.08.053.
10. S. N. Chandler-Wilde, I. G. Graham, S. Langdon and M. Lindner. Condition number estimates for combined potential boundary integral operators in acoustic scattering. Journal of Integral Equations and Applications, 21, 229-279, (2009).
11. D. J. Needham, S. Langdon, G. S. Busswell and J. P. Gilchrist. The unsteady flow of a weakly compressible fluid in a thin porous layer. I: Two-dimensional theory. SIAM J. Appl. Math., 69, 1084-1109, (2009).
12. J. F. Blowey, J. R. King and S. Langdon. Small- and waiting-time behaviour of the thin-film-equation. SIAM J. Appl. Math., 67, 1776-1807, (2007).
13. S. N. Chandler-Wilde and S. Langdon. A Galerkin boundary element method for high frequency scattering by convex polygons. SIAM J. Numer. Anal., 45, 610-640, (2007).
14. M. Ganesh, S. Langdon and I. H. Sloan. Efficient evaluation of highly oscillatory acoustic scattering surface integrals. J. Comput. Appl. Math., 204, 363-374, (2007).
15. S. Arden, S. N. Chandler-Wilde and S. Langdon. A collocation method for high frequency scattering by convex polygons. J. Comput. Appl. Math., 204, 334-343, (2007).
16. S. Langdon and S. N. Chandler-Wilde. A wavenumber independent boundary element method for an acoustic scattering problem. SIAM J. Numer. Anal., 43, 2450-2477, (2006).
17. S. N. Chandler-Wilde, S. Langdon and L. Ritter. A high wavenumber boundary element method for an acoustic scattering problem. Phil. Trans. R. Soc. Lond. A., 362, 647-671, (2004).
18. J. W. Barrett, S. Langdon and R. Nurnberg. Finite element approximation of a sixth order nonlinear degenerate parabolic equation. Numer. Math., 96, 401-434, (2004).
19. S. Langdon and I. G. Graham. Boundary integral methods for singularly perturbed boundary value problems. IMA J. Numer. Anal. 21, 217-237, (2001)

Refereed Conference Proceedings

20. S. N. Chandler-Wilde, D. P. Hewett, S. Langdon and A. Twigger. A high frequency BEM for scattering by non-convex obstacles. Proc. 10th International Conference on Mathematical and Numerical Aspects of Wave Propagation, pp.307-310, 2011.
21. S. Langdon and S. N. Chandler-Wilde. Boundary element methods for high frequency scattering problems. Mathematisches Forschungsinstitut Oberwolfach, Report No. 10/2010, DOI: 10.4171/OWR/2010/10, pp. 60-63, 2010.
22. S. N. Chandler-Wilde, S. Langdon and A. Twigger. High frequency boundary element methods for scattering by non-convex obstacles: a model problem, pages 86-87, Proceedings of Waves 2009, the 9th International Conference on Mathematical and Numerical Aspects of Wave Propagation, 15-19 June 2009, Pau, France.
23. M. Mokgolele, S. Langdon and S. N. Chandler-Wilde, High frequency scattering by a convex polygon with impedance boundary condition, pages 280-281, Proceedings of Waves 2009, the 9th International Conference on Mathematical and Numerical Aspects of Wave Propagation, 15-19 June 2009, Pau, France.
24. S. N. Chandler-Wilde, S. Langdon and M. Mokgolele. Numerical methods for high frequency acoustic scattering problems. Proceedings of the Institute of Acoustics, Vol.30, pt 2, 2008.
25. M. Mokgolele, S. N. Chandler-Wilde and S. Langdon. A boundary element method for high frequency scattering by convex curvilinear polygons. Proc. 8th Int. Conf. on Mathematical and Numerical Aspects of Wave Propagation, Reading University, pages 96-98, (2007).
26. J. M. Melenk and S. Langdon. An hp-boundary element method for high frequency scattering by convex polygons. Proc. 8th Int. Conf. on Mathematical and Numerical Aspects of Wave Propagation, Reading University, pages 93-95, (2007).
27. S. Langdon, D. Huybrechs and S. N. Chandler-Wilde. A fully discrete collocation method for high frequency scattering by convex polygons. Proc. 8th Int. Conf. on Mathematical and Numerical Aspects of Wave Propagation, Reading University, pages 84-86, (2007).
28. S. N. Chandler-Wilde, I. G. Graham, S. Langdon and M. Lindner. Condition Number Estimates for Combined Potential Integral Operators in Acoustic Scattering. Proc. 8th Int. Conf. on Mathematical and Numerical Aspects of Wave Propagation, Reading University, pages 47-49, (2007).
29. S. Langdon and S. N. Chandler-Wilde. Implementation of a boundary element method for high frequency scattering by convex polygons. Proc. 5th U.K. Conf. on Boundary Integral Methods, (K. Chen ed.), pages 2-11, (2005).
30. S. Langdon, M. Ganesh and I. H. Sloan. Approximation of high frequency acoustic wave surface integrals. Proc. 7th Int. Conf. on Mathematical and Numerical Aspects of Wave Propagation, Brown University, Providece, RI, pages 157-159, (2005).
31. S. N. Chandler-Wilde and S. Langdon. A boundary element method for high frequency scattering by convex polygons. Proc. 7th Int. Conf. on Mathematical and Numerical Aspects of Wave Propagation, Brown University, Providece, RI, pages 151-153, (2005).
32. S. Langdon and S. N. Chandler-Wilde. A GTD-based boundary element method for a surface scattering problem. Proceedings of the Institute of Acoustics 25(5), pages 224-233, (2003).
33. S. Langdon and S. N. Chandler-Wilde. A Galerkin boundary element method for an acoustic scattering problem, with convergence rate independent of frequency. Proc. 4th U.K. Conf. on Boundary Integral Methods, (S. Amini ed.), pages 67-76, Salford University Press (2003).
34. S. N. Chandler-Wilde, S. Langdon and L. Ritter. A Galerkin boundary element method for a high frequency scattering problem. Proc. 6th Int. Conf. on Mathematical and Numerical Aspects of Wave Propagation, University of Jyväskylä, Finland (G. C. Cohen, E. Heikkola, P. Joly and P. Neittaanmäki, eds), pages 257-262, Springer-Verlag, Berlin (2003).
35. S. Langdon. A boundary integral equation method for the heat equation. Proc. 5th Int. Conf. on Integral Methods in Science and Engineering (IMSE98), Michigan Technological University, (A. Struthers and B. Bertram, editors), pages 211-216.. Boca Raton FL: CRC (2000).

Other publications

36. Domain Embedding Boundary Integral Equation Methods and Parabolic PDEs, Ph.D. Thesis, University of Bath, 1999.
37. S. Langdon, N. Biggs, P. Chamberlain and J.-R. Li, Editorial for Waves 2007 conference, Journal of Computational and Applied Mathematics, (2009), doi: 10.1016/j.cam.2009.08.006.