Two families of primitive minimally triangle-saturated graphs

نویسندگان

  • Roger B. Eggleton
  • James MacDougall
چکیده

The authors have previously shown [1] that to generate all trianglesaturated graphs (graphs of diameter at most 2), it suffices to begin with the primitive minimally triangle-saturated graphs. In the present paper two infinite families of primitive minimally triangle-saturated graphs are constructed: one family covers all odd orders n ≥ 3, the other all even orders n ≥ 4, and in each case all graphs of order n produced have the same size. For each order n ≥ 3, the number of primitive minimally triangle-saturated graphs of order n yielded by the relevant construction is exponentially quadratic in n.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Minimally triangle-saturated graphs: adjoining a single vertex

A graph G is triangle-saturated if every possible edge addition to G creates one or more new triangles (3-cycles). Such a graph is minimally triangle-saturated if removal of any edge from G leaves a graph that is not triangle-saturated. This paper investigates adding a single new vertex to a triangle-saturated graph so as to produce a new trianglesaturated graph, and determines the conditions u...

متن کامل

Planar graphs with $\Delta\geq 7$ and no triangle adjacent to a $C_4$ are minimally edge and total choosable

For planar graphs, we consider the problems of list edge coloring and list total coloring. Edge coloring is the problem of coloring the edges while ensuring that two edges that are adjacent receive different colors. Total coloring is the problem of coloring the edges and the vertices while ensuring that two edges that are adjacent, two vertices that are adjacent, or a vertex and an edge that ar...

متن کامل

Triangle-Intersecting Families of Graphs

A family of graphs F is triangle-intersecting if for every G,H ∈ F , G∩H contains a triangle. A conjecture of Simonovits and Sós from 1976 states that the largest triangle-intersecting families of graphs on a fixed set of n vertices are those obtained by fixing a specific triangle and taking all graphs containing it, resulting in a family of size 182 (n2). We prove this conjecture and some gene...

متن کامل

On the Odd Cycles of Normal Graphs

A graph is normal if there exists a cross-intersecting pair of set families one of which consists of cliques while the other one consists of stable sets, and furthermore every vertex is obtained as one of these intersections. It is known that perfect graphs are normal while Cs, CT. and (_: are not. We conjecture that these three graphs are the only minimally not normal graphs. We give sufficien...

متن کامل

Computer algebra investigation of known primitive triangle-free strongly regular graphs

With the aid of computer algebra systems COCO and GAP with its packages we are investigating all seven known primitive triangle-free strongly regular graphs on 5, 10, 16, 50, 56, 77 and 100 vertices. These graphs are rank 3 graphs, having a rich automorphism group. The embeddings of each graph from this family to other ones are described, the automorphic equitable partitions are classified, all...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2005