arXiv subjects

A. El Kacimi

Publications and source records attributed to A. El Kacimi.

2 recordsLinked to original sources

arXiv2006

Skew-product for group-valued edge labellings of Bratteli diagrams

Group valued edge labellings $λ$ of a Bratteli diagram $B$ give rise to a skew-product Bratteli diagram $B(λ)$ on which the group acts. The quotient by the group action of the associated dynamics can be a nontrivial extension of the dynamics of $B$. We exhibit a Bratteli diagram for this quotient and construct a morphism to $B$ with unique path lifting property. This is shown to be an isomorphism for the dynamics if a property `loops lifting to loops' is satisfied by $B(λ)\to B$.

math.DS↗

arXiv2006

The K-group of substitutional systems

In another article we associated a dynamical system to a non-properly ordered Bratteli diagram. In this article we describe how to compute the $K-$group $K_0$ of the dynamical system in terms of the Bratteli diagram. In the case of properly ordered Bratteli diagrams this description coincides with what is already known, namely the so-called dimension group of the Bratteli diagram. The new ordered group defined here is more relevant for non-properly ordered Bratteli diagrams. We use our main result to describe $K_0$ of a substitutional system.

math.DS↗