Download or read book Characters and Cyclotomic Fields in Finite Geometry written by Bernhard Schmidt and published by Springer. This book was released on 2004-10-14 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph contributes to the existence theory of difference sets, cyclic irreducible codes and similar objects. The new method of field descent for cyclotomic integers of presribed absolute value is developed. Applications include the first substantial progress towards the Circulant Hadamard Matrix Conjecture and Ryser`s conjecture since decades. It is shown that there is no Barker sequence of length l with 13