Broue-Enguehard maps and Atkin-Lehner involutions

Abstract

Let a be one of the ten integers such that the sum of their divisors divide 24. For each such e, (except 15) we give a map from an algebra of polynomial invariants of some finite group to the algebra of modular forms invariant under the Atkin-Lehner group of level e. These maps are motivated and inspired by constructions of modular lattices from self-dual codes over rings. This work generalizes Broue-Enguehard work in level one and three obtained from binary and ternary codes. (c) 2007 Elsevier Ltd. All rights reserved.