&Wedderga;

Wedderburn Decomposition of Group Algebras

Version &VERSION;
Osnel Broche Cristo osnel@ufla.br

              Departamento de Ciências Exatas,
              Universidade Federal de Lavras - UFLA,
              Campus Universitário - Caixa Postal 3037,
              37200-000, Lavras - MG, Brazil

Allen Herman aherman@math.uregina.ca http://www.math.uregina.ca/˜aherman/

              Department of Mathematics and Statistics,

              University of Regina,

              3737 Wascana Parkway,

              Regina, SK, S0G 0E0, Canada

Alexander Konovalov alexk@mcs.st-andrews.ac.uk http://www.cs.st-andrews.ac.uk/˜alexk/

              School of Computer Science, University of St Andrews

              Jack Cole Building, North Haugh,

              St Andrews, Fife, KY16 9SX, Scotland

Aurora Olivieri olivieri@usb.ve

              Departamento de Matemáticas

    	      Universidad Simón Bolívar

              Apartado Postal 89000, Caracas 1080-A, Venezuela

Gabriela Olteanu gabriela.olteanu@econ.ubbcluj.ro http://math.ubbcluj.ro/˜olteanu

              Department of Statistics-Forecasts-Mathematics

              Faculty of Economics and Business Administration

              Babes-Bolyai University

              Str. T. Mihali 58-60, 400591 Cluj-Napoca, Romania

Ángel del Río adelrio@um.es http://www.um.es/adelrio

              Departamento de Matemáticas, Universidad de Murcia

              30100 Murcia, Spain

Inneke Van Gelder ivgelder@vub.ac.be http://homepages.vub.ac.be/~ivgelder

              Vrije Universiteit Brussel, Departement Wiskunde

              Pleinlaan 2

              1050 Brussels, Belgium

&RELEASEDATE;
&Wedderga; package The title ``&Wedderga;'' stands for ``WEDDERburn decomposition of Group Algebras. This is a &GAP; package to compute the simple components of the Wedderburn decomposition of semisimple group algebras of finite groups over finite fields and over subfields of finite cyclotomic extensions of the rationals. It also contains functions that produce the primitive central idempotents of semisimple group algebras and a complete set of orthogonal primitive idempotents. Other functions of &Wedderga; allow to construct crossed products over a group with coefficients in an associative ring with identity and the multiplication determined by a given action and twisting.
©right; 2006-&RELEASEYEAR; by Osnel Broche Cristo, Allen Herman, Alexander Konovalov, Aurora Olivieri, Gabriela Olteanu, Ángel del Río and Inneke Van Gelder.

&Wedderga; is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. For details, see the FSF's own site http://www.gnu.org/licenses/gpl.html.

If you obtained &Wedderga;, we would be grateful for a short notification sent to one of the authors. If you publish a result which was partially obtained with the usage of &Wedderga;, please cite it in the following form:

O. Broche Cristo, A. Herman, A. Konovalov, A. Olivieri, G. Olteanu, Á. del Río and I. Van Gelder. Wedderga --- Wedderburn Decomposition of Group Algebras, Version &VERSION;; &RELEASEYEAR; (http://www.cs.st-andrews.ac.uk/~alexk/wedderga).
We all are very grateful to Steve Linton for communicating the package and to the referee for careful testing &Wedderga; and useful suggestions. Also we acknowledge very much the members of the &GAP; team: Thomas Breuer, Alexander Hulpke, Frank Lübeck and many other colleagues for helpful comments and advise. We would like also to thank Thomas Breuer for the code of PrimitiveCentralIdempotentsByCharacterTable for rational group algebras.

On various stages the development of the Wedderga package was supported by the following institutions: University of Murcia; Francqui Stichting grant ADSI107; M.E.C. of Romania (CEEX-ET 47/2006); D.G.I. of Spain; Fundación Séneca of Murcia; CAPES and FAPESP of Brazil; Research Foundation Flanders (FWO - Vlaanderen). We acknowledge with gratitude this support.
<#Include SYSTEM "intro.xml"> <#Include SYSTEM "decomp.xml"> <#Include SYSTEM "SSP.xml"> <#Include SYSTEM "idempot.xml"> <#Include SYSTEM "crossed.xml"> <#Include SYSTEM "auxiliar.xml"> <#Include SYSTEM "div-alg.xml"> <#Include SYSTEM "applications.xml"> <#Include SYSTEM "theory.xml">