{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,21]],"date-time":"2026-04-21T16:56:55Z","timestamp":1776790615285,"version":"3.51.2"},"reference-count":57,"publisher":"American Mathematical Society (AMS)","issue":"267","license":[{"start":{"date-parts":[[2010,1,30]],"date-time":"2010-01-30T00:00:00Z","timestamp":1264809600000},"content-version":"am","delay-in-days":365,"URL":"https:\/\/www.ams.org\/publications\/copyright-and-permissions"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Math. Comp."],"abstract":"<p>\n                    In the present work, we investigate the applicability of the method of fundamental solutions for the solution of boundary value problems of elliptic partial differential equations and elliptic systems. More specifically, we study whether linear combinations of fundamental solutions can approximate the solutions of the boundary value problems under consideration. In our study, the singularities of the fundamental solutions lie on a prescribed\n                    <italic>pseudo\u2013boundary<\/italic>\n                    \u2014 the boundary of a domain which\n                    <italic>embraces<\/italic>\n                    the domain of the problem under consideration. We extend previous density results of Kupradze and Aleksidze, and of Bogomolny, to more general domains and partial differential operators, and with respect to more appropriate norms. Our domains may possess holes and their boundaries are only required to satisfy a rather weak boundary requirement, namely the\n                    <italic>segment condition<\/italic>\n                    . Our density results are with respect to the norms of the spaces\n                    <inline-formula content-type=\"math\/mathml\">\n                      <mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" alttext=\"upper C Superscript script l Baseline left-parenthesis normal upper Omega overbar right-parenthesis\">\n                        <mml:semantics>\n                          <mml:mrow>\n                            <mml:msup>\n                              <mml:mi>C<\/mml:mi>\n                              <mml:mi>\n                                \u2113\n                                \n                              <\/mml:mi>\n                            <\/mml:msup>\n                            <mml:mo stretchy=\"false\">(<\/mml:mo>\n                            <mml:mover>\n                              <mml:mi mathvariant=\"normal\">\n                                \u03a9\n                                \n                              <\/mml:mi>\n                              <mml:mo accent=\"false\">\n                                \u00af\n                                \n                              <\/mml:mo>\n                            <\/mml:mover>\n                            <mml:mo stretchy=\"false\">)<\/mml:mo>\n                          <\/mml:mrow>\n                          <mml:annotation encoding=\"application\/x-tex\">C^\\ell (\\overline {\\Omega })<\/mml:annotation>\n                        <\/mml:semantics>\n                      <\/mml:math>\n                    <\/inline-formula>\n                    . Analogous density results are obtainable with respect to H\u00f6lder norms. We have studied approximation by fundamental solutions of the Laplacian, biharmonic and\n                    <inline-formula content-type=\"math\/mathml\">\n                      <mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" alttext=\"m minus\">\n                        <mml:semantics>\n                          <mml:mrow>\n                            <mml:mi>m<\/mml:mi>\n                            <mml:mo>\n                              \u2212\n                              \n                            <\/mml:mo>\n                          <\/mml:mrow>\n                          <mml:annotation encoding=\"application\/x-tex\">m-<\/mml:annotation>\n                        <\/mml:semantics>\n                      <\/mml:math>\n                    <\/inline-formula>\n                    harmonic and modified Helmholtz and poly\u2013Helmholtz operators. In the case of elliptic systems, we obtain analogous density results for the Cauchy\u2013Navier operator as well as for an operator which arises in the linear theory of thermo\u2013elasticity. We also study alternative formulations of the method of fundamental solutions in cases when linear combinations of fundamental solutions of the equations under consideration are not dense in the solution space. Finally, we show that linear combinations of fundamental solutions of operators of order\n                    <inline-formula content-type=\"math\/mathml\">\n                      <mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\" alttext=\"m greater-than-or-equal-to 4\">\n                        <mml:semantics>\n                          <mml:mrow>\n                            <mml:mi>m<\/mml:mi>\n                            <mml:mo>\n                              \u2265\n                              \n                            <\/mml:mo>\n                            <mml:mn>4<\/mml:mn>\n                          <\/mml:mrow>\n                          <mml:annotation encoding=\"application\/x-tex\">m\\ge 4<\/mml:annotation>\n                        <\/mml:semantics>\n                      <\/mml:math>\n                    <\/inline-formula>\n                    , with singularities lying on a prescribed pseudo\u2013boundary, are not in general dense in the corresponding solution space.\n                  <\/p>","DOI":"10.1090\/s0025-5718-09-02191-7","type":"journal-article","created":{"date-parts":[[2009,4,27]],"date-time":"2009-04-27T13:47:33Z","timestamp":1240840053000},"page":"1399-1434","source":"Crossref","is-referenced-by-count":42,"title":["Applicability and applications of the method of fundamental solutions"],"prefix":"10.1090","volume":"78","author":[{"given":"Yiorgos-Sokratis","family":"Smyrlis","sequence":"first","affiliation":[]}],"member":"14","published-online":{"date-parts":[[2009,1,30]]},"reference":[{"key":"1","isbn-type":"print","volume-title":"Handbook of mathematical functions with formulas, graphs, and mathematical tables","year":"1992","ISBN":"https:\/\/id.crossref.org\/isbn\/0486612724"},{"key":"2","series-title":"Pure and Applied Mathematics (Amsterdam)","isbn-type":"print","volume-title":"Sobolev spaces","volume":"140","author":"Adams, Robert A.","year":"2003","ISBN":"https:\/\/id.crossref.org\/isbn\/0120441438","edition":"2"},{"key":"3","first-page":"1625","article-title":"On the question of a practical application of a new approximation method","volume":"2","author":"Aleksidze, M. A.","year":"1966","journal-title":"Differencial\\cprime nye Uravnenija","ISSN":"https:\/\/id.crossref.org\/issn\/0374-0641","issn-type":"print"},{"key":"4","series-title":"{\\cyr Spravochnaya Matematicheskaya Biblioteka}. [Mathematical Reference Library]","isbn-type":"print","volume-title":"{\\cyr Fundamental\\cprime nye funktsii v priblizhennykh resheniyakh granichnykh zadach}","author":"Aleksidze, M. A.","year":"1991","ISBN":"https:\/\/id.crossref.org\/isbn\/5020142514"},{"key":"5","unstructured":"E. Almansi, Sull\u2019integrazione dell\u2019equazione differenziale \u0394\u00b2=0, Atti. Reale. Accad. Sci. Torino 31 (1896), 881\u2013888."},{"key":"6","doi-asserted-by":"crossref","unstructured":"\\bysame, Sull\u2019integrazione dell\u2019equazione differenziale \u0394\u00b2\u207f=0, Annali di Mathematica Pura et Applicata, Series III 2 (1898), 1\u201351.","DOI":"10.1007\/BF02419286"},{"key":"7","unstructured":"C. J. S. Alves, Inverse scattering with spherical incident waves, Mathematical and numerical aspects of wave propagation (Golden, CO, 1998), SIAM, Philadelphia, PA, 1998, pp. 502\u2013504."},{"key":"8","series-title":"Oxford Mathematical Monographs","isbn-type":"print","volume-title":"Polyharmonic functions","author":"Aronszajn, Nachman","year":"1983","ISBN":"https:\/\/id.crossref.org\/isbn\/0198539061"},{"issue":"4","key":"9","doi-asserted-by":"publisher","first-page":"644","DOI":"10.1137\/0722040","article-title":"Fundamental solutions method for elliptic boundary value problems","volume":"22","author":"Bogomolny, Alexander","year":"1985","journal-title":"SIAM J. Numer. Anal.","ISSN":"https:\/\/id.crossref.org\/issn\/0036-1429","issn-type":"print"},{"key":"10","doi-asserted-by":"publisher","first-page":"134","DOI":"10.2307\/2372809","article-title":"Approximation by solutions of partial differential equations","volume":"84","author":"Browder, Felix E.","year":"1962","journal-title":"Amer. J. Math.","ISSN":"https:\/\/id.crossref.org\/issn\/0002-9327","issn-type":"print"},{"issue":"3-5","key":"11","doi-asserted-by":"publisher","first-page":"359","DOI":"10.1016\/S0898-1221(01)00292-9","article-title":"Multilevel compact radial functions based computational schemes for some elliptic problems","volume":"43","author":"Chen, C. S.","year":"2002","journal-title":"Comput. Math. Appl.","ISSN":"https:\/\/id.crossref.org\/issn\/0898-1221","issn-type":"print"},{"key":"12","doi-asserted-by":"crossref","unstructured":"A. H.-D. Cheng, H. Antes, and N. Ortner, Fundamental solutions of products of Helmholtz and polyharmonic operators, Eng. Anal. Bound. Elem. 14 (1994), no. 2, 187\u2013191.","DOI":"10.1016\/0955-7997(94)90095-7"},{"key":"13","unstructured":"H. A. Cho, M. A. Golberg, A. S. Muleshkov, and X. Li, Trefftz methods for time dependent partial differential equations, Comput. Mat. Cont. 1 (2004), no. 1, 1\u201337."},{"key":"14","unstructured":"A. Doicu, Y. Eremin, and T. Wriedt, Acoustic and Electromagnetic Scattering Analysis using Discrete Sources, Academic Press, New York, 2000."},{"key":"15","doi-asserted-by":"publisher","first-page":"713","DOI":"10.2307\/2033379","article-title":"On the theory of kernels of Schwartz","volume":"7","author":"Ehrenpreis, Leon","year":"1956","journal-title":"Proc. Amer. Math. Soc.","ISSN":"https:\/\/id.crossref.org\/issn\/0002-9939","issn-type":"print"},{"issue":"1-2","key":"16","doi-asserted-by":"publisher","first-page":"69","DOI":"10.1023\/A:1018981221740","article-title":"The method of fundamental solutions for elliptic boundary value problems","volume":"9","author":"Fairweather, Graeme","year":"1998","journal-title":"Adv. Comput. Math.","ISSN":"https:\/\/id.crossref.org\/issn\/1019-7168","issn-type":"print"},{"key":"17","doi-asserted-by":"crossref","unstructured":"G. Fairweather, A. Karageorghis, and P. A. Martin, The method of fundamental solutions for scattering and radiation problems, Eng. Anal. Bound. Elem. 27 (2003), 759\u2013769.","DOI":"10.1016\/S0955-7997(03)00017-1"},{"issue":"1-2","key":"18","doi-asserted-by":"publisher","first-page":"55","DOI":"10.1007\/s10444-004-1808-6","article-title":"A matrix decomposition MFS algorithm for axisymmetric biharmonic problems","volume":"23","author":"Fairweather, Graeme","year":"2005","journal-title":"Adv. Comput. Math.","ISSN":"https:\/\/id.crossref.org\/issn\/1019-7168","issn-type":"print"},{"key":"19","series-title":"Pure and Applied Mathematics (New York)","isbn-type":"print","volume-title":"Real analysis","author":"Folland, Gerald B.","year":"1999","ISBN":"https:\/\/id.crossref.org\/isbn\/0471317160","edition":"2"},{"key":"20","unstructured":"D. Gilbarg and N. S. Trudinger, Elliptic partial differential equations of second order, second ed., Grundlehren der Mathematischen Wissenschaften, vol. 224, Springer-Verlag, Berlin, 1983."},{"key":"21","isbn-type":"print","volume-title":"Discrete projection methods for integral equations","author":"Golberg, M. A.","year":"1997","ISBN":"https:\/\/id.crossref.org\/isbn\/1853124400"},{"key":"22","isbn-type":"print","doi-asserted-by":"publisher","first-page":"103","DOI":"10.1007\/BF01200068","article-title":"The method of fundamental solutions for potential, Helmholtz and diffusion problems","author":"Golberg, M. A.","year":"1999","ISBN":"https:\/\/id.crossref.org\/isbn\/1853125296"},{"key":"23","isbn-type":"print","volume-title":"Table of integrals, series, and products","author":"Gradshteyn, I. S.","year":"2000","ISBN":"https:\/\/id.crossref.org\/isbn\/0122947576","edition":"6"},{"key":"24","series-title":"Grundlehren der mathematischen Wissenschaften [Fundamental Principles of Mathematical Sciences]","isbn-type":"print","doi-asserted-by":"publisher","DOI":"10.1007\/978-3-642-96750-4","volume-title":"The analysis of linear partial differential operators. I","volume":"256","author":"H\u00f6rmander, Lars","year":"1983","ISBN":"https:\/\/id.crossref.org\/isbn\/3540121048"},{"issue":"2","key":"25","doi-asserted-by":"publisher","first-page":"434","DOI":"10.1016\/0021-9991(87)90176-8","article-title":"The method of fundamental solutions for the numerical solution of the biharmonic equation","volume":"69","author":"Karageorghis, Andreas","year":"1987","journal-title":"J. Comput. Phys.","ISSN":"https:\/\/id.crossref.org\/issn\/0021-9991","issn-type":"print"},{"key":"26","doi-asserted-by":"crossref","unstructured":"\\bysame, The Almansi method of fundamental\u2013solutions for solving biharmonic problems, Int. J. Numer. Meth. Engng. 26 (1988), no. 7, 1665\u20131682.","DOI":"10.1002\/nme.1620260714"},{"issue":"1","key":"27","first-page":"135","article-title":"A mathematical study of the charge simulation method. II","volume":"36","author":"Katsurada, Masashi","year":"1989","journal-title":"J. Fac. Sci. Univ. Tokyo Sect. IA Math.","ISSN":"https:\/\/id.crossref.org\/issn\/0040-8980","issn-type":"print"},{"issue":"3","key":"28","first-page":"635","article-title":"Asymptotic error analysis of the charge simulation method in a Jordan region with an analytic boundary","volume":"37","author":"Katsurada, Masashi","year":"1990","journal-title":"J. Fac. Sci. Univ. Tokyo Sect. IA Math.","ISSN":"https:\/\/id.crossref.org\/issn\/0040-8980","issn-type":"print"},{"issue":"1","key":"29","doi-asserted-by":"publisher","first-page":"123","DOI":"10.1007\/BF03167903","article-title":"On the numerical stability of the method of fundamental solution applied to the Dirichlet problem","volume":"5","author":"Kitagawa, Takashi","year":"1988","journal-title":"Japan J. Appl. Math.","ISSN":"https:\/\/id.crossref.org\/issn\/0910-2043","issn-type":"print"},{"key":"30","unstructured":"J. A. Ko\u0142odziej, Zastosowanie metody kollokacji brzegowej w zagadnieniach mechaniki. (Polish) [Applications of the Boundary Collocation Method in Applied Mechanics], Wydawnictwo Politechniki Pozna\u0144skiej, Pozna\u0144, 2001."},{"key":"31","first-page":"1118","article-title":"On a method of solving approximately the limiting problems of mathematical physics","volume":"4","author":"Kupradze, V. D.","year":"1964","journal-title":"\\v{Z}. Vy\\v{c}isl. Mat i Mat. Fiz.","ISSN":"https:\/\/id.crossref.org\/issn\/0044-4669","issn-type":"print"},{"key":"32","volume-title":"Potential methods in the theory of elasticity","author":"Kupradze, V. D.","year":"1965"},{"key":"33","first-page":"529","article-title":"An approximate method of solving certain boundary-value problems","volume":"30","author":"Kupradze, V. D.","year":"1963","journal-title":"Soob\\v{s}\\v{c}. Akad. Nauk Gruzin. SSR"},{"key":"34","unstructured":"V. D. Kupradze, T. G. Gegelia, M. O. Basheleshvili, and T. V. Burchuladze, Trekhmernye zadachi matematichesko\u012d teorii uprugosti i termouprugosti. (Russian) [Three\u2013dimensional problems in the mathematical theory of elasticity and thermoelasticity.], Izdat. \u201cNauka\u201d, Moscow, 1976."},{"key":"35","doi-asserted-by":"crossref","unstructured":"P. K. Kythe, Fundamental solutions for differential operators and applications, Birkh\u00e4user, Boston, MA, 1996.","DOI":"10.1007\/978-1-4612-4106-5"},{"key":"36","volume-title":"A treatise on the Mathematical Theory of Elasticity","author":"Love, A. E. H.","year":"1944"},{"key":"37","doi-asserted-by":"crossref","unstructured":"M. Maiti and S. K. Chakrabarty, Integral equation solutions for simply supported polygonal plates, Int. J. Engng. Sci. 12 (1974), no. 10, 793\u2013806.","DOI":"10.1016\/0020-7225(74)90017-2"},{"key":"38","doi-asserted-by":"crossref","first-page":"271","DOI":"10.5802\/aif.65","article-title":"Existence et approximation des solutions des \u00e9quations aux d\u00e9riv\u00e9es partielles et des \u00e9quations de convolution","volume":"6","author":"Malgrange, Bernard","year":"1955","journal-title":"Ann. Inst. Fourier (Grenoble)","ISSN":"https:\/\/id.crossref.org\/issn\/0373-0956","issn-type":"print"},{"issue":"4","key":"39","doi-asserted-by":"publisher","first-page":"638","DOI":"10.1137\/0714043","article-title":"The approximate solution of elliptic boundary-value problems by fundamental solutions","volume":"14","author":"Mathon, Rudolf","year":"1977","journal-title":"SIAM J. Numer. Anal.","ISSN":"https:\/\/id.crossref.org\/issn\/0036-1429","issn-type":"print"},{"issue":"2","key":"40","first-page":"31","article-title":"Uniform approximations of functions of a complex variable","volume":"7","author":"Mergelyan, S. N.","year":"1952","journal-title":"Uspehi Matem. Nauk (N.S.)"},{"key":"41","unstructured":"M. Nicolescu, Les fonctions polyharmoniques, Hermann, Paris, 1936."},{"key":"42","series-title":"McGraw-Hill Series in Higher Mathematics","volume-title":"Functional analysis","author":"Rudin, Walter","year":"1973"},{"issue":"1","key":"43","doi-asserted-by":"publisher","first-page":"229","DOI":"10.1007\/BF02400416","article-title":"Zur Theorie der Eindeutigen Analytischen Functionen","volume":"6","author":"Runge, C.","year":"1885","journal-title":"Acta Math.","ISSN":"https:\/\/id.crossref.org\/issn\/0001-5962","issn-type":"print"},{"key":"44","series-title":"Publications de l'Institut de Math\\'{e}matiques de l'Universit\\'{e} de Strasbourg [Publications of the Mathematical Institute of the University of Strasbourg]","volume-title":"Th\\'{e}orie des distributions. Tome I","volume":"9","author":"Schwartz, L.","year":"1950"},{"issue":"1","key":"45","doi-asserted-by":"publisher","first-page":"163","DOI":"10.1007\/s10543-006-0043-6","article-title":"The method of fundamental solutions: a weighted least-squares approach","volume":"46","author":"Smyrlis, Yiorgos-Sokratis","year":"2006","journal-title":"BIT","ISSN":"https:\/\/id.crossref.org\/issn\/0006-3835","issn-type":"print"},{"key":"46","doi-asserted-by":"crossref","unstructured":"Y.-S. Smyrlis, Mathematical foundation of the MFS for certain elliptic systems in linear elasticity, Numer. Math. (2009), DOI: 10.1007\/s00211-008-0207.1.","DOI":"10.1007\/s00211-008-0207-1"},{"key":"47","doi-asserted-by":"crossref","unstructured":"\\bysame, Approximations by solutions of elliptic equations in semilocal spaces, J. Math. Anal. Appl. 350 (2009), no. 1, 122\u2013134.","DOI":"10.1016\/j.jmaa.2008.09.049"},{"key":"48","unstructured":"Y.-S. Smyrlis and A. Karageorghis, The under\u2013determined version of the MFS: Taking more sources than collocation points, Submitted for publication."},{"issue":"1","key":"49","doi-asserted-by":"publisher","first-page":"29","DOI":"10.1023\/B:NUMA.0000016581.85429.8d","article-title":"A linear least-squares MFS for certain elliptic problems","volume":"35","author":"Smyrlis, Yiorgos-Sokratis","year":"2004","journal-title":"Numer. Algorithms","ISSN":"https:\/\/id.crossref.org\/issn\/1017-1398","issn-type":"print"},{"issue":"3","key":"50","doi-asserted-by":"publisher","first-page":"495","DOI":"10.1051\/m2an:2004023","article-title":"Numerical analysis of the MFS for certain harmonic problems","volume":"38","author":"Smyrlis, Yiorgos-Sokratis","year":"2004","journal-title":"M2AN Math. Model. Numer. Anal.","ISSN":"https:\/\/id.crossref.org\/issn\/0764-583X","issn-type":"print"},{"key":"51","unstructured":"P. Sundqvist, Numerical Computations with Fundamental Solutions (Numeriska ber\u00e4kingar med fundamentall\u00f6sningar), Ph.D. thesis, University of Uppsala, Faculty of Science and Technology, May 2005."},{"key":"52","series-title":"Mathematical Topics","isbn-type":"print","volume-title":"The Cauchy problem for solutions of elliptic equations","volume":"7","author":"Tarkhanov, Nikolai N.","year":"1995","ISBN":"https:\/\/id.crossref.org\/isbn\/3055016637"},{"key":"53","unstructured":"E. Trefftz, Ein Gegenst\u00fcck zum Ritzschen Verfahren, 2^{_l} Intern. Kongr. f\u00fcr Techn. Mech., Z\u00fcrich, 1926, pp. 131\u2013137."},{"key":"54","series-title":"Mathematics and its Applications, Vol. 6","volume-title":"Linear partial differential equations with constant coefficients: Existence, approximation and regularity of solutions","author":"Tr\u00e8ves, Fran\u00e7ois","year":"1966"},{"issue":"3","key":"55","doi-asserted-by":"publisher","first-page":"507","DOI":"10.1002\/num.20104","article-title":"Numerical analysis of the method of fundamental solutions for harmonic problems in annular domains","volume":"22","author":"Tsangaris, Th.","year":"2006","journal-title":"Numer. Methods Partial Differential Equations","ISSN":"https:\/\/id.crossref.org\/issn\/0749-159X","issn-type":"print"},{"issue":"1","key":"56","doi-asserted-by":"publisher","first-page":"137","DOI":"10.1016\/S0377-0427(03)00559-4","article-title":"Error estimates for a fundamental solution method applied to reduced wave problems in a domain exterior to a disc","volume":"159","author":"Ushijima, Teruo","year":"2003","journal-title":"J. Comput. Appl. Math.","ISSN":"https:\/\/id.crossref.org\/issn\/0377-0427","issn-type":"print"},{"key":"57","doi-asserted-by":"publisher","first-page":"513","DOI":"10.2307\/2039124","article-title":"Uniform approximation by solutions of elliptic equations","volume":"41","author":"Weinstock, Barnet M.","year":"1973","journal-title":"Proc. Amer. Math. Soc.","ISSN":"https:\/\/id.crossref.org\/issn\/0002-9939","issn-type":"print"}],"container-title":["Mathematics of Computation"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/www.ams.org\/mcom\/2009-78-267\/S0025-5718-09-02191-7\/S0025-5718-09-02191-7.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"},{"URL":"https:\/\/www.ams.org\/mcom\/2009-78-267\/S0025-5718-09-02191-7\/S0025-5718-09-02191-7.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,21]],"date-time":"2026-04-21T16:08:06Z","timestamp":1776787686000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ams.org\/mcom\/2009-78-267\/S0025-5718-09-02191-7\/"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2009,1,30]]},"references-count":57,"journal-issue":{"issue":"267","published-print":{"date-parts":[[2009,7]]}},"alternative-id":["S0025-5718-09-02191-7"],"URL":"https:\/\/doi.org\/10.1090\/s0025-5718-09-02191-7","archive":["CLOCKSS","Portico"],"relation":{},"ISSN":["1088-6842","0025-5718"],"issn-type":[{"value":"1088-6842","type":"electronic"},{"value":"0025-5718","type":"print"}],"subject":[],"published":{"date-parts":[[2009,1,30]]}}}