4 papers
Conjugacy classes of regular integer matrices
Claus Hertling, Khadija Larabi
This paper is devoted to the theory of -conjugacy classes of regular integer matrices. Such a matrix is -conjugate to the companio…
Semigroups from full lattices in commutative -algebras
Claus Hertling, Khadija Larabi
The full lattices in a finite dimensional commutative -algebra form a commutative semigroup. In the case of an algebraic number field the top part of a certain quotien…
Odd vanishing cycles in cyclotomic fields
Claus Hertling, Khadija Larabi
A cusp of a Hecke group has two natural lifts to the ring of integers of a cyclotomic field. These lifts are called here odd vanishing cycles. All lifts of all cusps together…
Unimodular bilinear lattices, automorphism groups, vanishing cycles, monodromy groups, distinguished bases, braid group actions and moduli spaces from upper triangular matrices
Claus Hertling, Khadija Larabi
This monograph starts with an upper triangular matrix with integer entries and 1's on the diagonal. It develops from this a spectrum of structures, which appear in different contex…