A Characterisation of Leech's Lattice.
Let be an algebraic number field and the ring of integers of . In this paper, we prove an analogue of Voronoï’s theorem for -lattices and the finiteness of the number of similar isometry classes of perfect -lattices.
We generalize Poor and Yuen’s inequality to the Hermite–Rankin constant and the Bergé–Martinet constant . Moreover, we determine explicit values of some low- dimensional Hermite–Rankin and Bergé–Martinet constants by applying Rankin’s inequality and some inequalities proven by Bergé and Martinet to explicit values of , and ().
A Lagrange Theorem in dimension 2 is proved in this paper, for a particular two dimensional continued fraction algorithm, with a very natural geometrical definition. Dirichlet type properties for the convergence of this algorithm are also proved. These properties proceed from a geometrical quality of the algorithm. The links between all these properties are studied. In relation with this algorithm, some references are given to the works of various authors, in the domain of multidimensional continued...