Talks I recently gave:

• The Lie algebra of an algebraic group.

  Given on 4 November 2002 in the local Leiden number theory seminar. [Notes.]

• Series of four talks on the calculation of characteristic p Katz modular forms of weight 1.

  Given on 10 December 2002, 15, 22 and 29 January 2003 in the local Leiden geometry seminar. [Notes.]

• Computations of weight 1 modular forms over finite fields.

  Given on 7 March 2003 in the Intercity number theory seminar. [Slides.]

• Berechnung von Modulformen von Gewicht 1 in positiver Charakteristik.

  Given on 6 May 2003 in the seminar on computational mathematics at Kassel. [Slides on request.]

• Series of two talks on an explicit adelic description of moduli of elliptic curves and Galois action on CM-points.

  Given on 26 May and 2 June 2003 in the local Leiden number theory seminar, having Shimura varieties as the current topic. [Notes.]

• Open problems: CM types acting on class groups.

  Given in October 2003 in the local Leiden number theory seminar, having Shimura varieties as the current topic. With this talk I try to draw attention to a purely number theoretic question (of Brauer-Siegel type) deriving from a problem posed by Bas Edixhoven. Progress on that question could be helpful for dealing with cases of the Andr�-Oort conjecture. [Notes]

• Mod p modular forms of weight one and Galois representations: computational and theoretical aspects.

  Given on 4 January 2004 at the Far Hills workshop on L-functions and p-adic cohomology: computational perspectives. [Slides on request.]

• Two talks On Fontaine's theory.

  Given on 18 February and 17 March 2004 in the local Leiden geometry seminar. [Notes on request.]

• Formes modulaires de Katz et repr�sentations di�drales.

  Given on 30 March 2004 at the Colloque Jeunes Chercheurs en th�orie des nombres. [Slides on request.]

• Dihedral Galois representations and Katz modular forms.

  Given on 14 May 2004 at the Intercity number theory seminar. [Video presentation on request.]

• Katz-Modulformen und Dieder-Galoisdarstellungen.

  Given on 14 September 2004 at the DMV-Jahrestagung in Heidelberg. [Slides on request.]

• Mod p modular symbols.

  Held in November 2004 at the Banff workshop Explicit methods in number theory. [Slides on request.]

• Modulformen, Heckeoperatoren und Anwendungen in der Zahlentheorie.

  Given on 8 December 2004 at Clausthal. [Video presentation on request.]

• Katz-Modulformen, Modulsymbole und die Serre-Vermutung.

  Given on 28 January 2005 at Regensburg. [Video presentation on request.]

• Mod p Modular Forms and Galois Representations.

  Given on 10 May 2005 at Barcelona.

• Mod p Modular Forms and Modular Symbols.

  Given on 24 May 2005 at Essen. [Video presentation on request.]

• Modular Forms of Weight One Over Finite Fields.

  Given on 2 September 2005 at the Intercity Number Theory Seminar in Leiden. [Video presentation on request.]

• Modular Forms: Numbers and Geometry.

  Given on 6 September 2005 in the lunch colloquium "This week's discoveries" of the faculty of science of Leiden University. [A streaming video and the video presentation.]

• Formes et symboles modulaires mod p.

  Given on 10 October 2005 at Strasbourg. [Video presentation.]

• Symboles modulaires et calcul de formes modulaires.

  Given on 11 April 2006 at Lausanne. [Notes.]

• Modulformen in expliziter Zahlentheorie

  Given on 6 July 2006 at Essen. [Notes on request.]

• Modular Forms mod p

  Series of four lectures given in August 2006 at the Graduate Summer Workshop on Computational Number Theory at the MSRI. [Notes.]

• Multiplicity Two

  Given on 11 October 2006 at the conference on Modular Forms, Schiermonnikoog, The Netherlands. [Notes on request.]

• Kryptographie mit elliptischen Kurven

  Tag der Naturwissenschaften, Regensburg, 15th November 2006. [Video presentation.]

• Inverse Galois Theory Via Modular Representations

  Given on 17 January 2007 in the Seminar Aachen-Köln-Lille-Siegen at Cologne. [Notes on request.]

• Multiplicities of Galois Representations of Weight 1

  Given on 6 June 2007 in Banff at the workshop Modular Forms: Arithmetic and Computation. Notes typed by Bjorn Poonen.

• Vortrag im Essener Seminar zur Einführung in die Theorie der automorphen Formen

  Given on 14 June 2007 in Essen. The notes are in a very rough form.

• Modular Forms in Inverse Galois Theory

  Given on 21 September 2007 in the Workshop "Galois Theory and Explicit Methods" at the Lorentz Center in Leiden. [Notes on request.]

• On the generation of the coefficient field of a newform by one Hecke eigenvalue

  Given on 6 November 2007 at the Humboldt-Universität in Berlin. [Notes on request.]

Last modification: 22 November 2007.