Cayley orders
Characteristic vectors of unimodular lattices which represent two
We improve the known upper bound of the dimension of an indecomposable unimodular lattice whose shadow has the third largest possible length, .
Class number formulas for quaternary quadratic forms
Class numbers of binary quadratic forms over algebraic number fields.
Class numbers of binary quadratic lattices over algebraic number fields
Class numbers of pairs of symmetric matrices
Classification of two genera of 32-dimensional lattices of rank 8 over the Hurwitz order.
Co-fibered products of algebraic curves
We give examples of failure of the existence of co-fibered products in the category of algebraic curves.
Composition of norm-type forms.
Computations of cyclotomic lattices.
Constructing Quasi-Pythagorean Fields
Coordinates of maximal roots of weakly non-negative unit forms
Cyclotomic modular lattices
Several interesting lattices can be realised as ideal lattices over cyclotomic fields : some of the root lattices, the Coxeter-Todd lattice, the Leech lattice, etc. Many of these are modular in the sense of Quebbemann. The aim of the present paper is to determine the cyclotomic fields over which there exists a modular ideal lattice. We then study an especially simple class of lattices, the ideal lattices of trace type. The paper gives a complete list of modular ideal lattices of trace type defined...