Let B be an abelian inner ideal and let KerL B be the kernel of B. In this paper we show that when there exists n ∈ N with [B,KerL B] n ⊂ B, the inner ideal B induces a bounded filtration in L where B is the first nonzero ...

The aim of this paper is to show how we can induce contact structures, contact metric structures and Sasaki structures on a null hypersurface from a rigging vector field. We give several explicit examples of this construction ...

For any n ≥ 2 and fixed k ≥ 1, we give necessary and sufficient conditions for an arbitrary nonzero square matrix in the matrix ring Mn(F) to be written as a sum of an invertible matrix U and a nilpotent matrix N with Nk ...

Let D denote the unit disc in C. We define the generalized Cesàro operator as follows: Cω( f )(z) = 1 0 f (t z) 1 z z 0 Bω t (u) du ω(t)dt, where {Bω ζ }ζ∈D are the reproducing kernels of the Bergman space ...

It is known that every finite group can be represented as the full group of automorphisms of a suitable compact dessin d’enfant. In this paper, we give a constructive and easy proof that the same holds for any countable ...

It is known that the ideals of a Leavitt path algebra LK (E) generated by Pl(E), by Pc(E) or by Pec(E) are invariant under isomorphism. Though the ideal generated by Pb∞ (E) is not invariant we find its “natural” replacement ...

Let F be a field. We show that given any nth degree monic polynomial q(x) ∈ F[x] and any matrix A ∈ Mn(F) whose trace coincides with the trace of q(x) and consisting in its main diagonal of k 0-blocks of order one, with k ...

The starting point of this work is the fact that the class of evolution algebras over a fixed field is closed under tensor product. We prove that, under certain conditions, the tensor product is an evolution algebra if and ...

We study the topology of all possible subsums of the generalized multigeometric series where are fixed positive real numbers and f runs along a certain class of non-negative functions on the unit interval. We detect ...

We will study evolution algebras A that are free modules of dimension two over domains. We start by making some general considerations about algebras over domains: They are sandwiched between a certain essential D-submodule ...