Lectures given at conferences
  1. Der Satz von Mordell-Weil via Methoden der Nonstandard Analysis.
    [The Theorem of Mordell-Weil via methods of nonstandard analysis]
    Modelltheorie (Anwendung der Modelltheorie auf die Zahlentheorie), Oberwolfach, 9-15 January 1977.
    {Tagungsbericht Oberwolfach 2/1977, p. 4}.
  2. The Theorem of Mordell-Weil via Nonstandard Methods.
    Algebraische Zahlentheorie (H. Hasse, P. Roquette), Oberwolfach, 14-20 August 1977.
    {Tagungsbericht Oberwolfach 33/1977, p. 16}.
  3. Nonstandard Diophantine Geometry.
    Recent Developments in Number Theory (P. Ribenboim), Queen's University, Kingston, Ontario; 2-20 July 1979.
    {Queen's Papers in Pure & Applied Math. 54 (1980), pp. 129-172}.
  4. Über rationale Punkte auf Kurven von Geschlecht g \ge 2 (Satz von Mumford).
    [On rational points on curves of genus g \ge 2 (Theorem of Mumford)]
    Algebraische Zahlentheorie (H. Hasse, P. Roquette), Oberwolfach, 12-18 August 1979.
    {Tagungsbericht Oberwolfach 34/1979, pp. 7-8}.
  5. Nonstandard Methods in Diophantine Geometry.
    Journées Arithmétiques 1980 (R. Odoni), Exeter, England, 13-19 April 1980.
    {London Math. Society Lecture Notes No. 56 (1982), pp. 417-449}.
  6. Die Mumfordsche Theorie der Thetafunktionen.
    [Mumford's theory of theta functions]
    AG Geyer-Harder: Die Vermutungen von Hodge und Tate (R.P. Langlands, M. Rapoport), Oberwolfach, 12-18 April 1981.
    {Tagungsbericht Oberwolfach 17/1981, pp. 6-7}.
  7. The number of non-rational subfields of a function field.
    Algebraische Zahlentheorie (W. Jehne, H. W. Leopoldt, P. Roquette), Oberwolfach, 9-15 August 1981.
    {Tagungsbericht Oberwolfach 35/1981, p. 11}.
  8. Thetafunktionen mehrerer Variablen.
    [Theta functions of several variables]
    AG Geyer-Harder: p-adische Uniformisierung (L. Gerritzen, M. van der Put), Oberwolfach, 12-17 April 1982.
    {Tagungsbericht Oberwolfach 15/1982, pp. 3-4}.
  9. Height pairings on curves.
    Conference on the Theory of Numbers, University of Alberta, Edmonton, 28-30 April 1983.
    {Rocky Mt. J. 15 (1985), pp. 417-449}.
  10. ``Real - analytic'' functions on nonarchimedean curves.
    p-adic Function Theory and Analysis (Y. Amice, L. Gerritzen), Oberwolfach, 10-16 February 1985.
    {Tagungsbericht Oberwolfach 9/1985, pp. 19}.
  11. Height pairings on curves.
    Journées arithmétiques, Besançon (France), 24-28 June 1985.
  12. Arithmetische Flächen and Potentialtheorie.
    [Arithmetic surfaces and potential theory]
    Algebraische Zahlentheorie (W. Jehne, H.W. Leopoldt, P. Roquette), Oberwolfach, 3-9 August 1986.
    {Tagungsbericht Oberwolfach 35/1986, pp. 14-16}.
  13. Idempotent relations and factors of Jacobians.
    78th Ontario Math Meeting, Toronto, 7 February 1987.
  14. Potential theory on curves.
    International Number Theory Conference (J.-M. De Koninck, C. Levesque), Québec, 5-18 July 1987.
    {Théorie des Nombres/Number Theory, W. de Gruyter, Berlin, 1989, pp. 475-543}.
  15. Potential theory on curves.
    OSU - Denison Mathematics Conference (J. S. Hsia), Denison OH, USA, 26-27 February 1988.
  16. Idempotent relations and invariants of algebraic varieties.
    First Conference of the Canadian Number Theory Association (R. A. Mollin), Banff, 17-27 April 1988.
  17. Arithmetic intersection theory.
    Algebraische Zahlentheorie (W. Jehne, H.W. Leopoldt, P. Roquette), Oberwolfach, Germany, 7-13 August 1988.
    {Tagungsbericht Oberwolfach, 35/1988, p. 10}.
  18. Green's functions on non-archimedean Riemann surfaces.
    AMS Meeting, Special Session on Arithmetic Intersection Theory. (H. Gillet), Chicago, 19-20 May 1989.
  19. Green's functions on non-archimedean Riemann surfaces.
    p-adic Analysis (F. Baldassarri, B. Dwork, S. Bosch), Trento, Italy, 28 May - 3 June 1989.
  20. Curves of genus two with reducible Jacobians.
    Second Conference of the Canadian Number Theory Association (D. Boyd), Vancouver, 20-26 August 1989.
  21. Kurven vom Geschlecht 2 mit elliptischen Differentialen.
    [Curves of genus 2 with elliptic differentials]
    Algebraische Zahlentheorie (W. Jehne, H. W. Leopoldt, P. Roquette), Oberwolfach, Germany, 12-18, August 1990.
    {Tagungsbericht Oberwolfach, 34/1990, pp. 7-8}.
  22. Curves of genus 2 with elliptic differentials and the Height Conjecture for elliptic curves.
    Conference on Finiteness Theorems in Number Theory (G. Frey), Essen, Germany, 12-15 March 1991.
    {Inst. Exp. Math. Essen, Preprint No. 18-1991, pp. 30-39}.   See also Errata et Addenda.
  23. Ends of metric spaces and arithmetic intersection theory.
    Algebraische Zahlentheorie (G. Frey, H.W. Leopoldt, P. Roquette), Oberwolfach, 2-8 August 1992.
    {Tagungsbericht Oberwolfach, 34/1992, pp. 12-13}.
  24. Abelian varieties over C and Theta-divisors.
    Advanced Workshop on Arithmetic Algebraic Geometry (A. Assadi, U. Jannsen, N. Schappacher), International Centre for Theoretical Physics, Trieste, Italy, 31 August - 11 September 1992.
    {ICTP Lecture Notes SMR. 637/34, 47 pp.}.
  25. Discriminants and regulator relations.
    Conference on Algebra and Number Theory (G. Frey, J. Ritter, H. Stichtenoth, E. Viehweg) Essen, Germany, 2-4 December 1992.
    {Algebra & Number Theory, W. de Gruyter, 1994, pp. 43-135}.
  26. Hermitian R[G]-modules and class number relations.
    Seaway Number Theory Conference, University of Toronto, Toronto, Ontario, 28-29 May 1993.
  27. The Noether formula.
    Advanced Workshop on Arithmetic Algebraic Geometry II, Ain Shams University, Cairo, Egypt, 4-15 September 1993.
    Lecture Notes (distributed to conference participants)
  28. Heights on abelian varieties and the theorem of Mordell-Weil.
    Advanced Workshop on Arithmetic Algebraic Geometry II, Ain Shams University, Cairo, Egypt, 4-15 September 1993.
    Lecture Notes (distributed to conference participants)
  29. Conjectural applications of arithmetic surfaces to number theory.
    Advanced Workshop on Arithmetic Algebraic Geometry II, Ain Shams University, Cairo, Egypt, 4-15 September 1993.
    Lecture Notes (distributed to conference participants)
  30. Hermitian ZG-modules and Brauer's Class Number Relation.
    Conference on L-functions (M. Kolster, V. Snaith), The Fields Institute, Waterloo, Ontario, 21-25 March 1994.
  31. Curves with elliptic differentials and the height conjecture for elliptic curves.
    Arithmetic Algebraic Geometry (A. Parshin, L. Szpiro), Luminy, France, 22-28 May 1994.
  32. Curves of genus 2 and the height conjecture for elliptic curves.
    International Conference on Arakelov Theory (U. Jannsen, N. Schappacher), Max-Planck Institute, Bonn, Germany, 1-7 June 1994.
    {Max-Planck Institute Preprints No. 1994-50, 3pp.}.
  33. Homology theory of Riemann surfaces.
    AG Oberwolfach on Boundedness of Torsion of Elliptic Curves over Number Fields (G. Frey, L. Merel), Oberwolfach, Germany, 9-15 October 1994.
    {Tagungsbericht Oberwolfach 43/1994, p. 12}.
  34. Modular Galois representations and curves of genus 2.
    Seaway Number Theory Conference (K. Williams), Carleton University, Ottawa, 9-10 June 1995.
  35. The construction of genus 2 covers of elliptic curves.
    Galois Workshop (D. Harbater), University of Pennsylvania, Philadelphia, USA, 20-22 October 1995.
  36. Diagonal quotient surfaces.
    Conference on Arithmetic Algebraic Geometry (H. Esnault, E. Viehweg, G. Frey), Institute for Experimental Mathematics, Essen, Germany, 21-24 November 1995.
  37. Applications of diagonal quotient surfaces to a problem of Mazur.
    Conference on Arithmetic Algebraic Geometry (H. Koch, J. Kramer, E.-W. Zink), Berlin, Germany, 21-26 March, 1996.
    {Max-Planck Institute für Mathematik Bonn Preprint No. 1996-51, 5pp.}
  38. Applications of diagonal quotient surfaces to a problem of Mazur.
    Conference on Number Theory (B. Burgess, I. Fesenko), Nottingham, England, 13-16 April, 1996.
  39. The Hecke algebra and modular representations.
    AG Oberwolfach on the Shimura-Taniyama Conjecture (G. Faltings, G. Frey), Oberwolfach, Germany, 7-11 October 1996
    {Tagungsbericht Oberwolfach 38/1996, p. 3}.
  40. Diagonal quotient surfaces and a problem of Mazur.
    CMS Winter Meeting, London Ontario, 7-11 December 1996.
  41. Diagonal quotient surfaces and a question of Mazur.
    Algebraic Number Theory (C. Deninger, G. Frey, P. Schneider, A. Scholl), Oberwolfach, Germany, 20-26 July 1997.
    {Tagungsbericht Oberwolfach 28/1997, p. 7-8}.
  42. Public Key Cryptography and Arithmetic Geometry.
    The Lorne Campbell Conference on Communications (B. Erdahl, F. Alajaji, S. Blostein), Queen's University, Kingston, 1 August 1997.
  43. Diagonal quotient surfaces and a question of Mazur.
    Number Theory and Arithmetical Geometry: Arithmetical Applications of Modular Forms (G. Frey, J. Bost), San Feliu de Guixols, Spain, 24-29 October 1997.
    Lecture (overhead slides)
  44. Mazur's question for mod 11 Galois representations.
    ICM-1998 Satellite Conference on Algebraic and Arithmetic Geometry (H. Esnault, G. Frey, E. Viehweg), Universität Essen, 10-14 August 1998. Lecture (overhead slides)
  45. Mazur's question for mod 11 Galois representations.
    Workshop on Algebraic Modular Forms and Modular Forms mod p (H. Darmon, M. Savin), CRM, University of Montreal, Montreal, 1-7 October 1998.
    Lecture (overhead slides)
  46. Unramified Galois covers of curves over number fields.
    Rosenfest: Conference in Honour of M. Rosen's 60th birthday (J. Silverman, J. Hoffstein), Brown University, Providence, RI, USA; 5-6 March 1999.
  47. Curves with an infinite K-rational geometric fundamental group.
    AMS Conference, Special Session on Galois Theory (J. Thompson, H. Völklein). University of Florida, Gainesville, Florida, 12-13 March 1999.
    Lecture (overhead slides)
  48. Curves with an infinite K-rational geometric fundamental group.
    Workshop on Arithmetical Algebraic Geometry (M. Goresky, K. Murty),CRM, Montreal, 14-18 May 1999.
  49. Unverzweigte Galoissche Überlagerungen von Kurven über Zahlkörpern.
    [Unramified Galois covers of curves over number fields]
    Deutsche Math. Ver. (DMV) Jahrestagung, Sektion Zahlentheorie, University of Mainz, Mainz, Germany, 5-11 September 1999.
  50. p-adic representations of the K-rational geometric fundamental group.
    Galois Actions and Geometry (P. Debes, H. Nakamura, A. Tamagawa), Math. Sci. Research Institute (MSRI), Berkeley, 11-15 October, 1999.
    Lecture (overhead slides)
  51. The state of the art of elliptic curve cryptography.
    CITO Conference: Layers of Security, CITO, Ottawa, 3 February, 2000.
    Lecture (overhead slides)
  52. Equivariant Atkin-Lehner Theory.
    Mini Workshop on Arithmetic Geometry (G. Frey), Inst. Exp. Math., Univ. Essen, 4-6 June 2000.
    Lecture (overhead slides)
  53. The Hurwitz space of genus 2 covers of an elliptic curve.
    AMS Conference, Special Session on Groups and Covering Spaces in Algebraic Geometry (M. Fried, H. Völklein), University of California, Irvine, 10-11 November 2001.
    Lecture (overhead slides)
  54. Modular Diagonal Quotient Surfaces.
    CRM Workshop on Hilbert Modular Varieties (H. Darmon, E. Goren), Far Hills Hotel (near Montreal), 3-6 January 2002.
    Lecture (overhead slides)
  55. The Hurwitz space of genus 2 covers of an elliptic curve.
    CMS Summer Conference, Special Session on Arithmetic Geometry, Université Laval, Québec, 15-17 June 2002.
    Lecture (overhead slides)
  56. The class number relations of Kronecker, Gierster and Hurwitz.
    CMS Summer Conference, Special Session on Number Theory, Université Laval, Québec, 15-17 June 2002.
    Lecture (overhead slides)
  57. Hurwitz spaces of covers of an elliptic curve.
    Quebec-Maine Conference (C. Levesque), Université Laval, Québec, 12-13 October 2002.
    Lecture (overhead slides)
  58. Applications of the Hurwitz space H_{E/K,N}.
    BIRS Workshop on Fundamental Groups, BIRS (Banff Center), Banff, Alberta, 06-20 September 2003.
  59. The number of covers of an elliptic curve.
    AMS Conference, Special Session on Group Actions on Curves University of North Carolina, Chapel Hill, NC 24-25 October 2003.
    Lecture (overhead slides)
  60. Endomorphisms of Jacobians of modular curves.
    60th Birthday Conference of G. Frey, University of Essen, Essen, Germany, 7-10 July 2004.
    Lecture (overhead slides)
  61. Mazur's Question and Modular Diagonal Quotient Surfaces.
    Quebec-Maine Conference (C. Levesque), U Laval, Quebec, 2-3 October 2004.
    Lecture (overhead slides)
  62. Endomorphisms of Jacobians of Modular Curves and an Application.
    CMS Conference, Special Session on Arithmetic Alebraic Geomerty (E. Goren, A. Iovita), Montreal, Quebec, 11-13 December 2004.
    Lecture (overhead slides)
  63. The Hasse-Weil Zeta Function of a Quotient Variety.
    CMS Conference, Special Session on L-functions and Algebraic Curves, Waterloo, Ontario, 4-6 June 2005.
    Lecture (overhead slides)
  64. A Galois theory for elliptic subfields of a genus 2 function field.
    AMS Conference, Special Session on Group Actions on Curves, Durham, New Hampshire, 22-23 April 2006.
    Lecture (overhead slides)
  65. Curves of genus 2 and a Conjecture of Gauss.
    Quebec-Maine Number Theory Conference (C. Levesque), Laval University, Quebec, 4-5 October 2008.
    Lecture (overhead slides)
  66. Curves of genus 2 and a Conjecture of Gauss.
    CMS Conference, Special Session in Number Theory, Ottawa, Ontario, 6-8 December 2008.
    Lecture (overhead slides)
  67. Binary Theta Series and CM Modular Forms.
    Quebec-Maine Number Theory Conference , Laval University, Quebec, 2-3 October 2010.
    Lecture (overhead slides)
  68. Der Ring der Modularkorrespondenzen [The Ring of Modular Correspondences].
    Tuebinger Colloquium Conference, IEM (=Institute of Experim. Math.), U Duisburg-Essen, 7 May 2011.
    Lecture (overhead slides)
  69. Binary Theta Series and Modular Forms with Complex Multiplication.
    AMS Conference, Special Session in Recent Directions in Number Theory (A. Cojocaru), University of Nebraska, Lincoln, NB, 14-16 October 2011.
    Lecture (overhead slides)
  70. Binary Theta Series and CM Modular Forms.
    AMS Conference, Special Session in Algebraic Number Theory (C. Levesque), University of Hawaii, Honolulu, USA, 3 March 2012.
    Lecture (overhead slides)
  71. The Ring of Modular Correspondences. Hawaii Conference in Algebraic Number Theory, Arithmetic Geometry, and Modular Forms (HCANTAGMF) (C. Levesque), University of Hawaii, Honolulu, USA, 6 March 2012.
    Lecture (overhead slides)
  72. Korrespondenzen und hyperelliptische Kurven [Correspondences and Hyperelliptic Curves].
    Tuebinger Colloquium Conference, U Augsburg, Augsburg, Germany, 2 June 2012.
    Lecture (overhead slides)
  73. Tensorprodukte von Galoisdarstellungen [Tensor products of Galois representations].
    Tuebinger Colloquium Conference, U Augsburg, Augsburg, Germany, 2 June 2012.
    Lecture (overhead slides)
  74. Tensor products of Galois representations.
    CMS Conference, Special Session in Algebraic Number Theory, Montreal, P.Q., 9 December 2012.
    Lecture slides
  75. Generalized Humbert Schemes and Intersections of Humbert Surfaces.
    AMS Conference, Special Session in Computational Advances in Special Functions and Tropical Geometry (E. Previato), University of Iowa, Ames, Iowa, 27 April 2013.
    Lecture (overhead slides)
  76. Verallgemeinerte Humbertsche Schemata und Durchschnitte von Humbert Flaechen. [Generalized Humbert Schemes and Intersections of Humbert Surfaces].
    Tuebinger Colloquium Conference, U Erlangen, Erlangen, Germany, 8 June 2013.
    Lecture (overhead slides)
  77. Tensor products of Galois representations.
    Ram Murty's 60th Birthday Conference CRM, Montreal, P.Q. 15 Oct 2013.
    Lecture (overhead slides)
  78. Hurwitz spaces for hyperelliptic curve covers.
    Conference in Algebra and Number Theory Tel Aviv University, Tel Aviv, Israel, 2 May 2014.
    Lecture (overhead slides)
  79. Perfect cuboids and the box variety.
    Quebec-Maine Number Theory Conference, Laval University, Quebec, 27 September 2014.
    Lecture slides
  80. Perfect cuboids and the box variety.
    CMS Conference, Section in Arithmetic Geometry (M. Kolster), McMaster University, Hamilton, Ontario, 7-8 December 2014.
    Lecture slides
  81. Subcovers of curves and moduli spaces.
    R.D. Accola Memorial Conference (E. Previato), Bosten University, Boston, MA, 19 March 2016.
    Lecture slides
  82. Perfekte Kuboide und die Kastenvarietaet. [Perfect cuboids and the box variety].
    Tuebinger Kolloquium Conference, U Duisburg-Essen, Essen, Germany, 21 May 2106.
    Lecture slides