A graph G is a k-dot product graph if there exists a vector labelling u : V (G) -> R(k) such that u(i)(T)u(j) >= 1 if and only if ij is an element of E(G). Fiduccia, Scheinerman, Trenk and Zito [Discrete Math., 1998] asked whether every planar graph is a 3-dot product graph. We show that the answer is "no". On the other hand, every planar graph is a 4-dot product graph. We also answer the corresponding questions for planar graphs of prescribed girth and for outerplanar graphs.
机构:
Department of Mathematics Texas A& M University Texarkana, Texarkana,TX,75503, United States
7101 University Ave, Texarkana,TX,75503, United StatesDepartment of Mathematics Texas A& M University Texarkana, Texarkana,TX,75503, United States
Bailey, Sean
论文数: 引用数:
h-index:
机构:
Brown, David
Snyder, Michael
论文数: 0引用数: 0
h-index: 0
机构:
Mathematics Department Snow College, Ephraim,UT,84627, United StatesDepartment of Mathematics Texas A& M University Texarkana, Texarkana,TX,75503, United States
Snyder, Michael
Turner, Nicole
论文数: 0引用数: 0
h-index: 0
机构:
Rock Ridge High School, Ashburn,VA,820148, United StatesDepartment of Mathematics Texas A& M University Texarkana, Texarkana,TX,75503, United States