Discusses a central problem in mathematics, which involves geometry, number theory, coding theory and group theory, centering on the study of extreme lattices, ... » 

Discusses a central problem in mathematics, which involves geometry, number theory, coding theory and group theory, centering on the study of extreme lattices, i.e. those on which the density attains a local maximum, and on so-called perfection property. Almost every chapter contains numerous exercises. It includes appendices on Semi-Simple Algebras and Quaternions and Strong Perfect Lattices. «