We prove that, for every positive integer k, there is an integer N such that every 3-connected graph with at least N vertices has a minor isomorphic to the k-spoke wheel or K3,k; and that every internally 4-connected graph with at least N vertices has a minor isomorphic to the 2k-spoke double wheel, the k-rung circular ladder, the k-rung Möbius ladder, or K4,k. We also prove an analogous result...

Self-adjusting networks (SANs) have the ability to adapt communication demand by dynamically adjusting workload (or demand) embedding, i.e., mapping of requests into network topology. SANs can reduce routing costs for frequently communicating node pairs paying a cost embedding. This is particularly beneficial when has structure, which to. Demand be represented in form graph, defined set nodes (...

We calculate the Smith normal form of the adjacency matrix of each of the following graphs or their complements (or both): complete graph, cycle graph, square of the cycle, power graph of the cycle, distance matrix graph of cycle, Andrásfai graph, Doob graph, cocktail party graph, crown graph, prism graph, Möbius ladder. The proofs operate by finding the abelianisation of a cyclically presented...

Given a graph G, the acyclic orientation graph of G, denoted AO(G), is the graph whose vertices are the acyclic orientations of G, and two acyclic orientations are joined by an edge in AO(G) iff they differ by the reversal of a single edge. A hamilton cycle in AO(G) gives a Gray code listing of the acyclic orientations of G. We prove that for certain graphs G, AO(G) is hamiltonian, and give exp...

An input constrained channel S is de ned as the set of words generated by a nite labeled directed graph It is shown that every nite state encoder with nite antici pation i e with nite decoding delay for S can be obtained through state splitting rounds applied to some deterministic graph presentation of S followed by a reduction of equivalent states Furthermore each splitting round can be restri...

This paper shows how to uniformly associate Lie algebras to the simply-laced Dynkin diagrams excluding E8 by constructing explicit combinatorial models of minuscule representations using only graph-theoretic ideas. This involves defining raising and lowering operators in a space of ideals of certain distributive lattices associated to sequences of vertices of the Dynkin diagram.

The aim of this work is to investigate the F-index and F-coindex of the line graphs of the cycle graphs, star graphs, tadpole graphs, wheel graphs and ladder graphs using the subdivision concepts. F-index of the line graph of subdivision graph of square grid graph, 2D-lattice, nanotube and nanotorus of TUC4C8[p, q] are also investigated here.

We prove polynomial upper bounds of geometric Ramsey numbers of pathwidth2 outerplanar triangulations in both convex and general cases. We also prove that the geometric Ramsey numbers of the ladder graph on 2n vertices are bounded by O(n3) and O(n10), in the convex and general case, respectively. We then apply similar methods to prove an nO(log(n)) upper bound on the Ramsey number of a path wit...

We outline a new algorithm to solve coupled systems of differential equations in one continuous variable x (resp. coupled difference equations in one discrete variable N) depending on a small parameter ε: given such a system and given sufficiently many initial values, we can determine the first coefficients of the Laurent-series solutions in ε if they are expressible in terms of indefinite nest...