Modular data are commonly studied in mathe- matics and physics. A modular datum defines a finite-dimensional representation of the modular group SL2(Z). In this paper, we show that there is a one-to-one correspondence ...

Let Γ be the modular group. We extend a non-trivial Γ-invariant equivalence relation on Qb to a general relation by replacing the group Γ0(n) by ΓK(n), and determine the suborbital graph F K u,n, an extended concept of ...

This paper is about sparse numerical semigroups and applications in the Weierstrass semigroups theory. We describe and find the genus of certain families of sparse numerical semigroups with Frobenius number even and we ...

A 2-monomial matrix over a commutative ring R is by definition any matrix of the form M(t, k, n) = Φ Ik 0 0 tIn−k , 0 < k < n, where t is a non-invertible element of R, Φ the companion matrix to λ n − 1 and Ik ...

In this paper, we characterize all finitely gene- rated multiplication R-modules whose the first nonzero Fitting ideal of them is contained in only finitely many maximal ideals. Also, we prove that a finitely generated ...

The rings we consider in this article are com- mutative with identity 1 6= 0 and are not fields. Let R be a ring. We denote the collection of all proper ideals of R by I(R) and the collection I(R) \ {(0)} by I(R) ∗ . ...

In 1995 D. V. Belkin described the lattice of quasivarieties of modules over principal ideal domains [1]. The following paper provides a description of the lattice of subquasivarieties of the variety of modules over a given ...