In this note we study embeddings of Cayley graphs of right groups on surfaces. We characterize those right groups which have a toroidal but no planar Cayley graph, such that the generating system of the right group has a minimal generating system of the group as a factor.

We consider contact processes on general Cayley graphs. It is shown that any such contact process has a well-defined exponential growth rate, which can be related to the configuration seen from a ‘typical’ infected site at a ‘typical’ late time. Using this quantity, it is proved that on any nonamenable Cayley graph, the critical contact process dies out.

The \arrowhead torus" is a broadcast graph that we deene on the 6-valent grid as a Cayley graph. We borrow the term from Mandelbrot who qualiies in that way one of the Sierpinski's famous fractal constructions. The 6-valent grid H = (V; E) is generated by three families of straight lines. We adopt the isotropic orientation S ! N, NE ! SW, NW ! SE and deene the system of generators S = fs 1 ; s ...

For a positive integer n, does there exist a vertex-transitive graph r on n vertices which is not a Cayley graph, or, equivalently, a graph r on n vertices such that Aut F is transitive on vertices but none of its subgroups are regular on vertices? Previous work (by Alspach and Parsons, Frucht, Graver and Watkins, MaruSic and Scapellato, and McKay and the second author) has produced answers to ...

We present a formulation of the Cayley-Hamilton theorem for hypermatrices in conjunction with the corresponding combinatorial interpretation. Finally we discuss how the formulation of the Cayley-Hamilton theorem for hyermatrices leads to new graph invariants which in some cases results in symmetry breakings among cospectral graphs.

In this paper we introduce a new class of double coset Cayley digraphs induced by quasigroups. These graphs can be considered as the generalization of Double Coset Cayley Digraphs induced by loops. Moreover, various graph properties are expressed in terms of algebraic properties. This did not attract much attention in the literature.

We investigate the existence of Hamilton paths in connected Cayley graphs on generalized dihedral groups. In particular, we show that a connected Cayley graph of valency at least three on a generalized dihedral group, whose order is divisible by four, is Hamiltonconnected, unless it is bipartite, in which case it is Hamilton-laceable.

Vadapalli and Srimani [2] have proposed a new family of Cayley graph interconnection networks of constant degree four. Our comments show that their proposed graph is not new but is the same as the wrap-around butterfly graph. The structural kinship of the proposed graph with the de Bruijn graph is also discussed.

We study those automatic sequences which are produced by an automaton whose underlying graph is the Cayley graph of a finite group. For 2-automatic sequences, we find a characterization in terms of what we call homogeneity, and among homogeneous sequences, we single out those enjoying what we call self-similarity. It turns out that self-similar 2-automatic sequences (viewed up to a permutation ...

This paper demonstrates the power of the Cayley graph approach to solve specific applications , such as rearrangement problems and the design of interconnection networks for parallel CPU's. Recent results of the authors for efficient use of Cayley graphs are used here in exploratory analysis to extend recent results of Babai et al. on a family of trivalent Cayley graphs associated with P SL 2 (...