Lattices and Codes

1 Lattices and Codes.- 1.1 Lattices.- 1.2 Codes.- 1.3 From Codes to Lattices.- 1.4 Root Lattices.- 1.5 Highest Root and Weyl Vector.- 2 Theta Functions and Weight Enumerators.- 2.1 The Theta Function of a Lattice.- 2.2 Modular Forms.- 2.3 The Poisson Summation Formula.- 2.4 Theta Functions as Modular Forms.- 2.5 The Eisenstein Series.- 2.6 The Algebra of Modular Forms.- 2.7 The Weight Enumerator of a Code.- 2.8 The Golay Code and the Leech Lattice.- 2.9 The MacWilliams Identity and Gleason's Theorem.- 2.10 Quadratic Residue Codes.- 3 Even Unimodular Lattices.- 3.1 Theta Functions with Spherical Coefficients.- 3.2 Root Systems in Even Unimodular Lattices.- 3.3 Overlattices and Codes.- 3.4 The Classification of Even Unimodular Lattices of Dimension 24.- 4 The Leech Lattice.- 4.1 The Uniqueness of the Leech Lattice.- 4.2 The Sphere Covering Determined by the Leech Lattice.- 4.3 Twenty-Three Constructions of the Leech Lattice.- 4.4 Embedding the Leech Lattice in a Hyperbolic Lattice.- 4.5 Automorphism Groups.- 5 Lattices over Integers of Number Fields and Self-Dual Codes.- 5.1 Lattices over Integers of Cyclotomic Fields.- 5.2 Construction of Lattices from Codes over ??p.- 5.3 Theta Functions over Number Fields.- 5.4 The Case p = 3: Ternary Codes.- 5.5 The Equation of the Tetrahedron and the Cube.- 5.6 The Case p = 5: the Icosahedral Group.- 5.7 Theta Functions as Hilbert Modular Forms (by N.-P. Skoruppa).