On wednesday afternoon the workshop turns into the AKLS seminar on automorphic forms.

14:00 - 14:05Welcome
14:05 - 15:05Jacques MartinetFrom positive definite quadratic forms to Euclidean lattices Slides
-- Coffee break --
16:00 - 16:30Bertrand MeyerSome constructions of maximal witness codes Slides
16:45 - 17:15Elisabeth NossekDual strongly perfect lattices Slides
17:30 - 18:00Rudolf Scharlau Extremality of modular forms, lattices and sphere packings
09:15 - 10:15Siegfried Boecherer Harmonic polynomials for quadratic forms with hermitian structure and associated theta series
-- Coffee break --
11:00 - 11:30Boris VenkovUnimodular lattices and strongly regular graphs (some examples and problems)
11:45 - 12:15Annika MeyerOn a recursive decoding algorithm for glued lattices Slides
-- Lunch --
14:00 - 15:00Wilhelm PleskenCodes and hyperplane arrangements
-- Coffee break --
16:00 - 16:30Richard ParkerIntegral laminated latticesSlides (odp)
16:45 - 17:30Rainer Schulze-Pillot-Ziemen On extremal modular forms
09:15 - 10:15Heinz-Georg Quebbemann Type II self-dual algebraic geometric codes
-- Coffee break --
11:00 - 11:30Manabu OuraSome consequences of the work of Nebe-Rains-Sloane
11:45 - 12:15Gabriele Nebe Automorphisms of extremal codes
-- Lunch --
14:00 - 14:05Welcome (Seminar Aachen-Köln-Lille-Siegen)
14:05 - 14:55Christine BachocLower bounds for the measurable chromatic number of Euclidean space Slides
15:00 - 15:50Valentin BlomerCounting rational points on a cubic surface
-- Coffee break --
17:00 - 17:50Jan BruinierOn the converse theorem for Borcherds products
-- Dinner --
09:00 - 09:20David LorchEinklassige Geschlechter 3-dimensionaler Gitter
09:30 - 09:50Michael Jürgens Nicht-Existenz extremaler Gitter: eine weitere Anwendung der Methode von Bachoc-VenkovSlides
10:00 - 10:20Juan Marcos Cerviño Infinitesimal aspects of the theta-series map
-- Coffee break --
11:00 - 11:20Stefan Höppner / Timo Rosnau Ganzzahlige orthogonale Darstellungen der zyklischen Gruppe, Teil ISlides
11:30 - 11:50Björn Hoffmann Ganzzahlige orthogonale Darstellungen der zyklischen Gruppe, Teil IISlides
12:00 - 12:20Jan JongenLattices over twisted group rings and rational forms of finite groups Slides



Jan Jongen: Lattices over twisted group rings and rational forms of finite groups

At first I will discuss the relationship between finite matrix groups which are defined over the rational numbers and modules over certain skew group rings K wreath G. These skew group rings come with a natural Z-order Z_K wreath G. Using this order I will show that in some cases it is possible to construct (algorithmically) the full (Z_K wreath G)-lattices in a given module V. In general this works along the same lines as the group ring case.