Representation of order automorphisms by words.
In the group theory various representations of free groups are used. A representation of a free group of rank two by the so-calledtime-varying Mealy automata over the changing alphabet is given. Two different constructions of such automata are presented.
We give combinatorial models for non-spherical, generic, smooth, complex representations of the group , where is a non-Archimedean locally compact field. More precisely we carry on studying the graphs defined in a previous work. We show that such representations may be obtained as quotients of the cohomology of a graph , for a suitable integer , or equivalently as subspaces of the space of discrete harmonic cochains on such a graph. Moreover, for supercuspidal representations, these models...
In this paper we represent every lattice by subgroups of free groups using the concept of the homotopy group of a graph.
For each integer and each finite graph , we construct a Coxeter group and a non positively curved polygonal complex on which acts properly cocompactly, such that each polygon of has edges, and the link of each vertex of is isomorphic to . If is a “generalized -gon”, then is a Tits building modelled on a reflection group of the hyperbolic plane. We give a condition on for to be non enumerable (which is satisfied if is a thick classical generalized -gon). On the other hand,...