Dr. Székelyhidi László tudományos előadásai

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  1. Spectral synthesis on locally compact Abelian groups, Budapest, Hungary: Analysis Seminar, Rényi Institute, September 28, 2023.
  2. New Results on Spectral Synthesis, Będlewo, Poland: 20th International Conference on Functional Equations and Inequalities, September 17-23, 2023.
  3. Remarks on non-discrete spectral synthesis. Cluj Napoca, Romania, Theodor Angheluta Seminar, July 11–13, 2023.
  4. New Results in Spectral Synthesis on Varieties Hajdúszoboszló, Hungary, 59th International Symposium on Functional Equations, June 18– 25, 2023.
  5. On a Generalization of The Heisenberg Group. The 22nd Debrecen–Katowice Winter Seminar, Hajdúszoboszló, Hungary, February 1-4, 2023.
  6. Kalahari Math – Secondary school mathematics competitions in Botswana. (in Hungarian) Pécs, Hungary, Scientific Meeting, Pécs Academic Committee, October 18, 2022.
  7. So, is it knowable or not? (in Hungarian) Pécs, Hungary, Scientific Meeting, Pécs Academic Committee, October 19, 2022.
  8. János Aczél In His Own Work. Innsbruck, Austria, 58nd International Symposium on Functional Equations, June 19–26, 2022.
  9. Spectral Analysis and Spectral Synthesis on Lie Groups. (in Hungarian) Debrecen, Hungary, Síkfőkút Analysis Seminar, Institute of Mathematics and Informatics, June 11-13, 2022.
  10. A Sneak Peak In The Ivory Tower – What does a mathematician count? (in Hungarian) Széchenyi University, Győr, Hungary, ”Műteremház”, February 23, 2022.
  11. A Sneak Peak In The Ivory Tower – What does a mathematician count? (in Hungarian) Hegyeshalom, Hungary, Community Center, February 20, 2022.
  12. Invariant Subspaces Over The Heisenberg Group. The 21st Debrecen– Katowice Winter Seminar, Brenna, Poland, February 2-5, 2022.
  13. A Sneak Peak In The Ivory Tower – What does a mathematician count? (in Hungarian) Dunakiliti, Hungary, Community Center, December 9, 2021.
  14. Moment Functions and Bell Polynomials. (in Hungarian) Debrecen, Hungary: Síkfőkút Analysis Seminar, Institute of Mathematics and Informatics, August 27-29, 2021.
  15. Functional Equations, Moment Functions and Bell Polynomials. Bedlewo, Poland: 19th International Conference on Functional Equations and Inequalities, August 12–18, 2021.
  16. Generalized Moment Functions on Hypergroups. (in Hungarian), Debrecen, Hungary: Síkfőkút Analysis Seminar, Institute of Mathematics and Informatics, June 28-30, 2020.
  17. Spectral Synthesis on the Affine Group of the Unitary Group, Debrecen, Hungary: HSA 2020 Harmonic and Spectral Analysis, Institute of Mathematics and Informatics, online, June 8-10, 2020.
  18. Spectral Analysis and Semi-simple Measure Algebras}, Debrecen, Hungary, Seminar talk, Institute of Mathematics, University of Debrecen, November 14, 2019.
  19. Quantum probability fields, random walks and hypergroups. (in Hungarian), Miskolc, Hungary, Seminar talk, Institute of Mathematics, University of Miskolc, November 12, 2019.
  20. Functional equations via spectral synthesis, Krakow, Poland, AGH University of Science and Technology, DEA 2019, September 16-20, 2019.
  21. Addition theorems, functional equations and spectral synthesis, Cluj Napoca, Romania, Theodor Angheluta Seminar, July 3-6, 2019.
  22. Functional Equations on Infinite Hypergroup Joins, Bedlewo, Poland: 18th International Conference on Functional Equations and Inequalities, June 9-15, 2019.
  23. Invariant Means and Their Applications (in Hungarian). Miskolc, Hungary, Seminar talk, Institute of Mathematics, University of Miskolc, November 7, 2018.
  24. Stability of functional equations related to spherical functions. Conference on Ulam’s Type Stability, Timisoara, Romania, October 8-13, 2018.
  25. Functional Equations for Exponential Polynomials. Debrecen, Hungary, Seminar talk, Institute of Mathematics, University of Debrecen, October 3, 2018.
  26. Professor Zoltán Daróczy is 80, Laudation talk. Hajdúszoboszló, Hungary, „Numbers, Functions, Equations NFE’18”, August 26 – September 1, 2018.
  27. Harmonic and Spectral Synthesis. Palapye, Botswana, International Workshop on Mathematical Analysis, BIUST, August 9, 2018.
  28. Spectral Synthesis and Invariant Differential Operators. Graz-Mariatrost, Austria: 56th International Symposium on Functional Equations,  June 17-24, 2018.
  29. Spherical Spectral Synthesis. Modern Methods and Applications of Operator Theory and Harmonic Analysis VIII, (OTHA), April 22-27, 2018, Rostov on Don, Russia
  30. Spectral Synthesis and Invariant Differential Operators. Debrecen, Hungary, International Spring Workshop on Mathematical Analysis, University of Debrecen, April 3, 2018.
  31. Spectral Synthesis on Affine Groups. Pécs, Hungary, 6th Workshop on Fourier Analysis and Related Fields, August 24-31, 2017,
  32. Exponential Polynomials on Affine Groups. Bedlewo, Poland: 17th International Conference on Functional Equations and Inequalities, July 9-15, 2017.
  33. Polynomial Functions on Affine Groups. Chengdu, China: 55th International Symposium on Functional Equations, Special Session, June 11-18, 2017.
  34. New Developments in the Theory of Spectral Analysis and Spectral Synthesis. Chengdu, China: 55th International Symposium on Functional Equations, June 11-18, 2017.
  35. Spectral analysis and synthesis. Mashad, Iran, Seminar talk at Ferdowsi University, February 22, 2017.
  36. Spectral synthesis on double coset hypergroups. Isfahan, Iran, IPM Institute for Research in Fundamental Sciences, February 21, 2017.
  37. Introduction and preliminaries of spectral analysis and synthesis. Qom, Iran, International Workshop on Mathematical Analysis, University of Qom, February 19, 2017.
  38. Spectral synthesis on discrete Abelian groups. Qom, Iran, International Workshop on Mathematical Analysis, University of Qom, February 19, 2017.
  39. Spectral synthesis on non-discrete Abelian groups. Qom, Iran, International Workshop on Mathematical Analysis, University of Qom, February 19, 2017.
  40. Spectral analysis and synthesis on hypergroups. Qom, Iran, International Workshop on Mathematical Analysis, University of Qom, February 19, 2017.
  41. Open problems on spectral analysis and synthesis. Applications. Qom, Iran, International Workshop on Mathematical Analysis, University of Qom, February 19, 2017.
  42. Functional equations on hypergroups. An introduction. Gaborone, Botswana, Department Seminar, University of Botswana,  February 2, 2017.
  43. Spectral Synthesis on Gelfand Pairs. Debrecen,Hungary, Research Seminar of the Institute of Mathematics, University of Debrecen, January 11, 2017.
  44. Spherical Spectral Synthesis. Hajdúszoboszló, Hungary, Conference on Inequalities and Applications CIA’16, August 28-September 3, 2016.
  45. Functional equations on affine groups. Hajdúszoboszló, Hungary: 54th International Symposium on Functional Equations, June 12-19, 2016.
  46. Remark on spectral synthesis. Hajdúszoboszló, Hungary: 54th International Symposium on Functional Equations, Remark, June 12-19, 2016.
  47. Hypergroups and Quantum Probability Spaces. Department Seminar, University of Botswana, Gaborone, Botswana, May 12, 2016.
  48. Mathematics and Adventure – Fermat’s Last Theorem, World Science Day, University of Botswana, Gaborone, Botswana, November 10, 2015.
  49. Discrete Spectral Synthesis Problems on Varieties, Budapest, Hungary, 5th Workshop on Fourier Analysis and Related Fields, 24-28 August, 2015
  50. Graph properties of additive and related functions. Department Seminar, University of Botswana, Gaborone, Botswana, August 20, 2015.
  51. Functional Equations on Discrete Abelian Groups. (in Hungarian) Debrecen, Hungary: Analysis Conference on the occasion of the 80th birthday of Sándor Kántor, Institute of Mathematics, University of Debrecen, July 3-5, 2015.
  52. On the graph of additive and related functions. Krynica, Poland, 53rd International Symposium on Functional Equations, June 14-21, 2015.
  53. Functional Equations and Stability Problems on Hypergroups. Bedlewo, Poland: 16th International Conference on Functional Equations and Inequalities, May 17-23, 2015
  54. On the powers of maximal ideals in the measure algebra, Debrecen, Hungary, Research Seminar, Department of Analysis, Institute of Mathematics, University of Debrecen, May 6, 2015. (via Skype)
  55. Spectral Analysis and Spectral Synthesis.Course for PhD students, Silesian University, Katowice Poland, November 3-7, 2014.
  56. Solving functional equations via spectral synthesis. Hajdúszoboszló, Hungary, Conference on Inequalities and Applications CIA’14, Szeptember 7-13, 2014.
  57. Discrete spectral synthesis on varieties. Seoul, South-Korea, International Congress of Mathematicians ICM2014, August 13-21, 2014.
  58. On the graph of additive functions. Innsbruck, Austria, 52nd International Symposium on Functional Equations, Remark, June 22-29, 2014.
  59. Remark on alien-like functional equations. Innsbruck, Austria, 52nd International Symposium on Functional Equations, Special session, June 22-29, 2014.
  60. A characterization of polynomial functions. Innsbruck, Austria, 52nd International Symposium on Functional Equations, June 22-29, 2014.
  61. Fréchet’s Functional Equation and Spectral Synthesis. University of Jaén, Seminar at the Department of Mathematics, Jaén, Spain, June 13, 2014.
  62. Spectral synthesis and difference equations. University of Granada, Seminar at the Department of Mathematics, Granada, Spain, June 12, 2014.
  63. Stability of functional equations on hypergroups. Conference on Ulam’s Type Stability, Rytro, Poland, June 2-6, 2014.
  64. Classes of polynomial functions. BIUST (Botswana International Univeristy of Science and Technology), Seminar at the Department of Mathematics, Gaborone, Botswana, March 19, 2014.
  65. Finite Dimensional Translation Invariant Function Spaces. University of Botswana, Seminar at the Department of Mathematics, Gaborone, Botswana, October 17, 2013.
  66. Spectral Synthesis on Abelian Groups. 4th Conference on Topology, Algebra, Analysis and Geometry, 11-13 September, 2013, Gaborone, Botswana
  67. Spectral Analysis and Synthesis on Abelian Groups. 4th Workshop on Fourier Analysis and Related Fields, 26-30 August, 2013, Budapest, Hungary
  68. On Exponential Polynomials. NFE Numbers, Functions, Equations 2013, Visegrád, Hungary, June 28–30, 2013.
  69. On Exponential Polynomials. The 13th Debrecen–Katowice Winter Seminar, Zakopane, Poland, January 27–30, 2013.
  70. Difference Equations and Spectral Synthesis. (in Hungarian) University of Pannonia, Seminar at the Institute of Mathematics, Veszprém, Hungary, November 13, 2012.
  71. The Lord of the Rings, the Lady of the Rings and the Spectral Synthesis. (in Hungarian) University of Debrecen, Seminar at the Institute of Mathematics, Debrecen, Hungary, November 8, 2012.
  72. A characterization of exponential polynomials. Katowice, Poland, Seminar at the Mathematical Institute, Silesian University, September 28, 2012.
  73. What is spectral synthesis? Krynica-Zdrój, Poland: Summer School 2012, Mathematical Institute, Silesian University, September 24–27, 2012.
  74. Remarks on spectral synthesis. München-Garching, Germany: Harmonic Analysis, Convolution Algebras, Special Functions 2012, September 10– 14, 2012.
  75. Spectral synthesis and the structure of polynomial functions. Hajdúszoboszló, Hungary: 50th International Symposium on Functional Equations, June 17–24, 2012.
  76. Spectral Synthesis on Vector Modules. The 12th Debrecen–Katowice Winter Seminar, Hajdúszoboszló, Hungary, January 26–29, 2012.
  77. Polynomial Functions on Abelian Groups. Bedlewo, Poland: 14th International Conference on Functional Equations and Inequalities, September 11–17, 2011.
  78. Spectral Synthesis Problems on Locally Compact Groups. Graz-Mariatrost, Austria: 49th International Symposium on Functional Equations, June 14–20, 2011.
  79. A Moment Problem on Hypergroups I.. The 11th Debrecen–Katowice Winter Seminar, Wisla, Poland, February 1–4, 2011.
  80. Studies on Hypergroups (in Hungarian) University of Debrecen, Hungary, March 31, 2011.
  81. Fibonacci’s Rabbits and Spectral Synthesis. (in Hungarian) University of Debrecen, Hungary, March 31, 2011.
  82. Spectral analysis and spectral synthesis Batz-sur-Mer, France: Plenary talk, 48th International Symposium on Functional Equations, June, 14– 20, 2010.
  83. Spectral Analysis on Commutative Hypergroups. The 10th Debrecen– Katowice Winter Seminar, Zamárdi, Hungary, February 3–6, 2010.
  84. Fourier series of mean periodic functions Budapest, Hungary: 3rd Workshop in Fourier Analysis and Related Fields, September, 17–23, 2009.
  85. Mean periodic functions Gargnano, Italy: 47th International Symposium on Functional Equations, June, 14–20, 2009.
  86. Transforms of mean periodic functions. Workshop on Dyadic Analysis and Related Areas with Applications, Dobogókő, Hungary, June 7-10, 2009.
  87. Mean periodic functions and Fourier transforms. (in Hungarian) University of Debrecen, Seminar at the Institute of Mathematics, Hungary, May 7, 2009.
  88. The Fourier transform of mean periodic functions. Special seminar, Columbia University, New York, NY, USA, April 20, 2009.
  89. Functional Equations on Hypergroups Opava, Czech Republik: 46th International Symposium on Functional Equations, June, 22–29, 2008.
  90. Spectral analysis and spectral synthesis. Special seminar, Harvard University, Boston, Cambridge, MA, USA, March 13, 2008.
  91. Spectral synthesis on hypergroups. The M60 conference on the occasion of the 60st birthday of Miklós Laczkovich, Rényi Institute, Budapest, Hungary, February 22– February 24, 2008.
  92. Spectral synthesis on Sturm–Liouville hypergroups. The 8th Debrecen– Katowice Winter Seminar, Poroszló, Hungary, January 30– February 2, 2008.
  93. Spectral Synthesis Problems on Locally Compact Groups. Conference on Inequalities and Applications ’07, Noszvaj, Hungary, September, 9–15, 2007.
  94. Spectral Synthesis. (in Hungarian) University of Debrecen, Seminar at the Institute of Mathematics, Hungary, April, 17, 2007.
  95. On Discrete Spectral Synthesis. Louisville, Kentucky, USA: 44th International Symposium on Functional Equations, May, 14–20, 2006.
  96. Superstability of moment functions on hypergroups. Louisville, Kentucky, USA: 44th International Symposium on Functional Equations, May, 14–20, 2006.
  97. Spectral Synthesis over Discrete Abelian Groups. Budapest, Hungary: Hungarian Academy of Sciences, May, 2006.
  98. Moment functions on Sturm–Liouville hypergroups. The 6th Debrecen– Katowice Winter Seminar, Berekfürdő, Hungary, February 1–4, 2006.
  99. Discrete Spectral Synthesis. Eger, Hungary: Fejér–Riesz Conference, June, 9–13, 2005.
  100. Polynomial Functions and Spectral Synthesis. Batz-sur-Mer, France: 43rd International Symposium on Functional Equations, May, 15–21, 2005.
  101. Regularity Theorems for Special Function Classes. Batz-sur-Mer, France: 43rd International Symposium on Functional Equations, Special Session, May, 15–21, 2005.
  102. Characterization of Polynomial Ideals. (in Hungarian) University of Debrecen, Seminar at the Institute of Mathematics, Hungary, February 17, 2005.
  103. Difference Equations on Polynomial Hypergroups II.. The 5th Debrecen– Katowice Winter Seminar, Bedlewo, Poland, February 2-5, 2005.
  104. The Singer, Not The Song… (In memoriam Jenő Erdős). (in Hungarian) University of Debrecen, Hungary, December 9, 2004.
  105. Partial Difference Equations and Spectral Synthesis. Opava, Czeh Republic: 42nd International Symposium on Functional Equations, June 20–27, 2004.
  106. Spectral Analysis and Spectral Synthesis on Polynomial Hypergroups. Budapest, Hungary: Probability Theory on Groups and Related Structures, International Conference on the occasion of Herbert Heyer’s retirement, August 2–6, 2004.
  107. Spectral Synthesis and Difference Equations. Seminar at the Department of Mathematics and Statistics, Sultan Qaboos University, Oman, February 18, 2004.
  108. Binomial Functional Equations on Polynomial Hypergroups. The 4th Debrecen–Katowice Winter Seminar, Mátraháza, Hungary, February 47, 2004.
  109. Spectral Synthesis on Torsion Groups. University of Debrecen, Seminar at the Institute of Mathematics, Hungary, January 22, 2004.
  110. Spectral Analysis and Spectral Synthesis. Seminar at the Department of Mathematics and Statistics, Sultan Qaboos University, Oman, November 19, 2003.
  111. Moment Functions on Hypergroups. Noszvaj, Hungary: 41st International Symposium on Functional Equations, June 8–15, 2003.
  112. Mean Periodic Functions. Mississippi State, MS, USA: Seminar at the Department of Mathematics and Statistics, Mississippi State University, Mississippi State, April 19, 2002.
  113. Spectral Synthesis. Seminar Series, Department of Mathematics, University of Louisville, Louisville, Kentucky, Spring Semester, 2002.
  114. Functional equations, Chebyshev polynomials, hypergroups. (in Hungarian) Debrecen, Hungary: Meeting dedicated to the 60th birthday of Professor László Losonczi, 2001.
  115. Hypergroups, Functional Equations. (in Hungarian) Debrecen, Hungary: 9th Síkfőkút Analysis Seminar, Institute of Mathematics and Informatics, June 15-17, 2001.
  116. Exponential Polynomials on Polynomial Hypergroups. Muszyna–Zlockie, Poland: 8th International Conference on Functional Equations and Inequalities, September 9–15, 2001.
  117. Polynomial Hypergroups and Functional Equations on Hypergroups. Sjandberg, Denmark: 39th International Symposium on Functional Equations, August 12–18, 2001.
  118. Conditional Expectation of Mean-periodic Functions. (in German) Dresden, Germany: Seminar talk at Technical University Dresden, May 2001.
  119. Mean Periodic Functions. (in Hungarian) Debrecen, Hungary: Seminar talk at Debrecen University, May 2001.
  120. Translation Invariant Function Spaces and Spectral Synthesis. (in Hungarian) Budapest, Hungary: Seminar talk at Budapest Technical University, April 2001.
  121. Functional Equations on Hypergroups. Cieszyn, Poland: 1st Katowice– Debrecen Winter Seminar on Functional Equations, February 7–10, 2001.
  122. On Discrete Spectral Synthesis. Noszvaj, Hungary: 38th International Symposium on Functional Equations, June 11–18, 2000.
  123. Stability Problems for Functional Equations. Cambridge, United Kingdom: Seminar talk at Trinity College, Cambridge University, May 2000.
  124. Convolution Type Functional Equations. Oxford, United Kingdom: Seminar talk at St.John’s College, Oxford University, May 2000.
  125. Functional Equations of Convolution Type. (in Hungarian) Budapest, Hungary: Hungarian Academy of Sciences, May 2000.
  126. Stability of Functional Equations. (in Hungarian) Veszprém, Hungary: Seminar of the Mathematical Institute of Veszprém University, February 2000.
  127. On a Functional Equation for a Two-variable Function. Muszyna, Poland: The Seventh International Conference on Functional Equations and Inequalities, September 12–18, 1999.
  128. Digital Filters and Functional Equations. (in Hungarian) Veszpr´em, Hungary: Meeting dedicated to the 60th birthday of Professors József Gróf and János Győrváry, 1999.
  129. On Discrete Spectral Synthesis. Budapest, Hungary: Functions, Series, Operators, Alexits Memorial Conference, Budapest, 1999.
  130. Remark on Mean-value Type Functional Equations. Huntington, West Virginia, USA: 37th International Symposium on Functional Equations, 1999.
  131. Exponential Polynomials and Functional Equations. (in Hungarian) Eger, Hungary: Seminar of the Eszterházy Károly Highschool, Eger, 1999.
  132. Discrete Spectral Synthesis. Debrecen, Hungary: 7th ”Síkfőkút Analysis Seminar”, Institute of Mathematics and Informatics, June 4-6, 1999.
  133. A Wiener Tauberian Theorem on Discrete Abelian Torsion Groups. (in Hungarian) Debrecen, Hungary: Conference on Analysis, Kossuth Lajos University, 1999.
  134. Spectral Synthesis and Functional Equations. (in German) Munich, Germany: Department of Mathematics, Technical University of Munich, 1998.
  135. On Convolution–type Functional Equations. (in German) Neuherberg, Germany: Workshop Harmonic Analysis and Wavelets, GSF-Forschungszentrum für Umwelt und Gesundheit, 1998.
  136. Exponential Polynomials and Fourier–transforms. (in German) Munich, Germany: Mathematics Seminar of the Technical University of Munich, 1998.
  137. Laudatio for Zoltán Daróczy. Noszvaj, Hungary: Numbers, Functions, Equations ’98, International Conference dedicated to the 60th birthday of Professors Zoltán Daróczy and Imre Kátai, 1998.
  138. On the Extension of Exponential Polynomials. Brno, Czech Republic: 36th International Symposium on Functional Equations, 1998.
  139. On Mean Periodic Functions. Graz, Austria: 35th International Symposium on Functional Equations, 1997.
  140. The Fourier–transform of Mean Periodic Functions. (in Hungarian) Budapest, Hungary: Seminar of the Eötvös Loránd University, Budapest, 1997.
  141. On the Stability of Functional Equations. (in Hungarian) Pécs, Hungary: Seminar of the Janus Pannonius University, Pécs, 1996.
  142. On the Stability of Linear Functional Equations. (in Hungarian) Síkfőkút, Hungary: ”In Memoriam György Szabó” Meeting, 1996.
  143. Hilbert Spaces. (in Hungarian) Debrecen, Hungary: Habilitation talk, Hungarian Academy of Sciences, 1995.
  144. On Cosine Operator Functions. Zamárdi, Hungary: 2nd Debrecen Graz Seminar, 1995.
  145. Characterization of Linear Operators by Stability Properties. Kuwait City, Kuwait: Mathematics Colloquium of the Department of Mathematics, Kuwait University, 1994.
  146. On the Stability of Homogeneous Functions. Krynica, Poland: The Fourth International Conference on Functional Equations and Inequalities, ”Stability”, 1993.
  147. Regularization and General Methods in the Theory of Functional Equations. Oberwolfach, Germany: 30th International Symposium on Functional Equations, 1992.
  148. Functional Equations and Spectral Synthesis. Kuwait City, Kuwait: Mathematics Colloquium of the Department of Mathematics, Kuwait University, 1992.
  149. On a Problem of M.Laczkovich. Wolfville, Nova Scotia, Canada: 29th International Symposium on Functional Equations, 1991.
  150. On Functional Equations Analoguous to Some Partial Differential Equations. Graz, Austria: 1st Debrecen -Graz Seminar, 1991.
  151. On Stability Theorems, (in Hungarian). Debrecen, Hungary: Meeting dedicated to ”Aczél -Daróczy”, 1991.
  152. Stability of Functional Equations in Several Variables. Graz, Austria: 28th International Symposium on Functional Equations, 1990.
  153. Functional Equations via Harmonic Analysis. Cosenza, Italy: Department of Mathematics, University of Calabria, 1990.
  154. Functional Equations via Spectral Synthesis, (seminar). Milan, Italy: Department of Mathematics, University of Milan, 1990.
  155. Convolution-type functional equations. Hamburg, Germany: International Congress on Mathematics for the 300th Anniversary of the Foundation of the Mathematical Society of Hamburg, 1990.
  156. Spectral synthesis and functional equations. Vienna, Austria: XII. Österreichischer Mathematikerkongress, 1989.
  157. Translation invariant subspaces and convolution-type functional equations. Bielsko-Biala, Katowice, Kraków, Poland: 27th International Symposium on Functional Equations, 1989.
  158. Funktionalanalytische Methoden in der Theorie der Funktionalgleichungen. Marburg, Germany: Mathematisches Institut der Universität Marburg, 1989.
  159. Stability of some functional equations in economics. Milan, Italy: Department of Mathematics, University of Milan, 1988.
  160. Stabilitätsfragen einiger Funktionalgleichungen in der Wirtschaftstheorie. (in German) Karlsruhe, Germany: Institute of Economics and Operation Research, University of Karlsruhe, 1988.
  161. Über die Funktionalgleichung von Levi-Civitá. (in German) Hamburg, Germany: Mathematisches Kolloquium der Universität Hamburg, 1988.
  162. Über einen Superstabilitätssatz. (in German) Graz, Austria: Mathematisches Kolloquium der Karl Franzens Universität, 1988.
  163. Über die Levi-Civitá-Funktionalgleichung. (in German) Graz, Austria: Mathematisches Kolloquium der Karl Franzens Universität, 1988.
  164. On a problem of S.Mazur. San Feliu de Quixols, Spain: 26th International Symposium on Functional Equations, 1988.
  165. On A Property of Exponential Functions. Hamburg, Germany: 25th International Symposium on Functional Equations, 1987.
  166. On the Extension of Local Polynomials. Bielsko-Biala, Poland: Department of Mathematics, Technical University Lódz, 1987.
  167. Local Polynomials and Functional Equations. Katowice, Poland: Institute of Mathematics, Silesian University, 1987.
  168. Extension Theorems for Functional Equations. Kraków, Poland: Institute of Mathematics, University of Mining and Metallurgy, 1987.
  169. On a Class of Linear Functional Equations. Szczawnicza, Poland: International Conference on Functional Equations, 1987.
  170. Spline Approximational Method for The Wave Equation. Varna, Bulgaria: Conference on Constructive Theory of Functions, 1987.
  171. On Addition Theorems. Noszvaj, Hungary: 3rd International Conference on Functional Equations and Inequalities, 1986.
  172. Polynomially Additive Functions. South Hadley, USA: 24th International Symposium on Functional Equations, 1986.
  173. Fourier Transformation und mittelperiodische Funktionen. (in German) Karlsruhe, Germany: Mathematisches Kolloquium der Universität Karlsruhe, 1986.
  174. Additivity -a general principle. Karlsruhe, Germany: Institute of Economics and Operation Research, University of Karlsruhe, 1986.
  175. Fourier Transformation und mittelperiodische Funktionen. Erlangen, Germany: Mathematisches Kolloquium der Universität Erlangen-Nürnberg, 1986.
  176. The Fourier Transform of Mean Periodic Functions. Graz, Austria: XI.Österreichischer Mathematikerkongress, 1985.
  177. Functional Equations and Transformations. Gargnano, Italy: 23rd International Symposium on Functional Equations, (special session), 1985.
  178. Hyers’s Theorem via Invariant Means. Gargnano, Italy: 23rd International Symposium on Functional Equations, 1985.
  179. Invariante Mittelwerten und der Satz von Hyers. Bern, Switzerland: Mathematisches Kolloquium der Universität Bern, 1985.
  180. Exponential Polynomials and Functional Equations. Oberwolfach, Germany: 22nd International Symposium of Functional Equations, 1984.
  181. The Fourier Transform of Exponential Polynomials. Debrecen, Hungary: International Conference on Generalized Functions, 1984.
  182. Lp-approximation by Splines. Varna, Bulgaria: Conference on Constructive Theory of Functions, 1984.
  183. Almost Periodicity in Functional Equations. Konolfingen, Switzerland: 21st International Symposium on Functional Equations, 1983.
  184. Regularit¨atseigenschaften von Exponentialpolynomen. Graz, Austria: Mathematisches Kolloquium der Karl Franzens Universität, 1983.
  185. Functional Differential Equations by Splines. Russe, Bulgaria: 2nd Conference on Differential Equations and Applications, 1982.
  186. Fastperiodische Funktionen und Funktionalgleichungen. (in German) Rostock, GDR: Mathematisches Kolloquium der Wilhelm Pieck Universit¨at, 1982.
  187. Exponential Polynomials. Oberwolfach, Germany: 20th International Symposium on Functional Equations, 1980.
  188. Functional Equations on Topological Groups. Debrecen, Hungary: 2nd International Conference on Functional Equations and Inequalities, 1979.
  189. Polynomials on Groups. Leibnitz, Austria: 18th International Symposium on Functional Equations, 1978.