Automorphisms of extremal even unimodular lattices CWC Barranquilla

Computation of unit groups of orders University of Pennsylvania in Philadelphia

Automorphisms of extremal codes Princeton Atlas Conference

Affine Weyl Groups Sommerschule GRK 1632, 8.9.2015 Marienheide.

Berechnung von Einheitengruppen von Ordnungen Baer Kolloquium, Würzburg, 30.05.2015

Automorphisms of extremal codes, ALCOMA, March 2015

Computing unit groups of orders with the Voronoi algorithm. Bad Boll, March 2014

Automorphisms of extremal codes and lattices, Hannover, November 2013

Extremal lattices, Graz, January 2013

Extremal lattices, Oberwolfach, August 2012

Extremal lattices and Codes, Oberwolfach, August 2011

Extremale Gitter, Braunschweig Juni 2011

What is a block? Muenster, March 2011

An extremal even unimodular lattice of dimension 72. RIMS, Kyoto, December 2010

Recognition of division algebras, DagDay, Eindhoven, March 2010

Lattices and modular forms. Third de Brun workshop, Galway, Dec. 2009
Lattices and spherical designs. Third de Brun workshop, Galway, Dec. 2009
Codes and invariant theory. Third de Brun workshop, Galway, Dec. 2009
Codes and invariant theory II. Third de Brun workshop, Galway, Dec. 2009

Integral forms of algebraic groups. Arjeh Cohen's birthday colloquium, de Kapellerput, May 28 2009

p-adic integral group rings of finite groups. StJohns, June 5 2009

On automorphism groups of Type II codes. (Marseille, April 1, 2009)

Codes and lattices, analogies and interactions. Talk at the conference
Codes, Invariants and Modular Forms at the MPI in Bonn

Selbstduale Codes und Invariantentheorie, Kolloquium Heidelberg 5.6.08

Slides of my lecture series on Self-dual codes and invariant theory at the conference New challenges in digital communications, Vlora, 28.4.-9.5.2008 The Type of a self-dual code.
Clifford-Weil groups.
Hecke operators for codes.

Lattices and spherical designs. Slides of my talk in Amsterdam, june 30, 2006

Codes and invariant theory. survey for the farewell symposium for Rob van der Waall

Gitter und Modulformen.
Survey article based on talk given at the 2002 DMV meeting in Halle.
Jahresbericht der DMV, 104. Band (2002), Heft 3, 123-142.
Folien des Vortrags