A criterion for some Hamiltonian graphs to be Hamilton-connected
نویسنده
چکیده
Let M = {G / Kn,n ~ G ~ Kn V for some n 2:: 3} where V is the join operation. The author and N.K. Khachatrian proved that a connected graph G of order at least 3 is Hamiltonian if d(u) + d(v) 2:: IN(u) U N(v) U N(w)1 for each triple of vertices U,V,w with d(u,v) = 2 and w E N(u) n N(v) (where N( x) is the neighborhood of x). Here we prove that a graph G satisfying the above conditions is Hamilton-connected if and only if G is 3-connected and G r:J. M.
منابع مشابه
Five-Connected Toroidal Graphs Are Hamiltonian
It is well known that not all 3-connected planar graphs are hamiltonian. Whitney [10] proved that every triangulation of the sphere with no separating triangles is hamiltonian. Tutte [9] proved that every 4-connected planar graph has a Hamilton cycle. Extending Tutte's technique, Thomassen [8] proved that every 4-connected planar graph is in fact Hamilton connected. (A small omission in [8] was...
متن کاملThomassen's conjecture implies polynomiality of 1-Hamilton-connectedness in line graphs
A graph G is 1-Hamilton-connected if G − x is Hamilton-connected for every x ∈ V (G), and G is 2-edge-Hamilton-connected if the graph G + X has a hamiltonian cycle containing all edges of X for any X ⊂ E+(G) = {xy| x, y ∈ V (G)} with 1 ≤ |X| ≤ 2. We prove that Thomassen’s conjecture (every 4-connected line graph is hamiltonian, or, equivalently, every snark has a dominating cycle) is equivalent...
متن کاملA Closure for 1-Hamilton-Connectedness in Claw-Free Graphs
A graph G is 1-Hamilton-connected if G − x is Hamilton-connected for every vertex x ∈ V (G). In the paper we introduce a closure concept for 1-Hamiltonconnectedness in claw-free graphs. If G is a (new) closure of a claw-free graph G, then G is 1-Hamilton-connected if and only if G is 1-Hamilton-connected, G is the line graph of a multigraph, and for some x ∈ V (G), G − x is the line graph of a ...
متن کاملA new constraint of the Hamilton cycle algorithm
Grinberg’s theorem is a necessary condition for the planar Hamilton graphs. In this paper, we use cycle bases and removable cycles to survey cycle structures of the Hamiltonian graphs and derive an equation of the interior faces in Grinberg’s Theorem. The result shows that Grinberg’s Theorem is suitable for the connected and simple graphs. Furthermore, by adding a new constraint of solutions to...
متن کاملHamilton cycles in 5-connected line graphs
A conjecture of Carsten Thomassen states that every 4-connected line graph is hamiltonian. It is known that the conjecture is true for 7-connected line graphs. We improve this by showing that any 5-connected line graph of minimum degree at least 6 is hamiltonian. The result extends to claw-free graphs and to Hamilton-connectedness.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Australasian J. Combinatorics
دوره 10 شماره
صفحات -
تاریخ انتشار 1994