Computing the Ramsey Number $R(K_5-P_3,K_5)$

نویسندگان

  • Jesse A. Calvert
  • Michael J. Schuster
  • Stanislaw P. Radziszowski
چکیده

We give a computer-assisted proof of the fact that R(K5 − P3,K5) = 25. This solves one of the three remaining open cases in Hendry’s table, which listed the Ramsey numbers for pairs of graphs on 5 vertices. We find that there exist no (K5−P3,K5)-good graphs containing a K4 on 23 or 24 vertices, where a graph F is (G, H)-good if F does not contain G and the complement of F does not containH. The unique (K5−P3,K5)good graph containing a K4 on 22 vertices is presented.

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

On the oriented perfect path double cover conjecture

‎An  oriented perfect path double cover (OPPDC) of a‎ ‎graph $G$ is a collection of directed paths in the symmetric‎ ‎orientation $G_s$ of‎ ‎$G$ such that‎ ‎each arc‎ ‎of $G_s$ lies in exactly one of the paths and each‎ ‎vertex of $G$ appears just once as a beginning and just once as an‎ ‎end of a path‎. ‎Maxov{'a} and Ne{v{s}}et{v{r}}il (Discrete‎ ‎Math‎. ‎276 (2004) 287-294) conjectured that ...

متن کامل

Zarankiewicz Numbers and Bipartite Ramsey Numbers

The Zarankiewicz number z(b; s) is the maximum size of a subgraph of Kb,b which does not contain Ks,s as a subgraph. The two-color bipartite Ramsey number b(s, t) is the smallest integer b such that any coloring of the edges of Kb,b with two colors contains a Ks,s in the rst color or a Kt,t in the second color.In this work, we design and exploit a computational method for bounding and computing...

متن کامل

THE ORDER GRAPHS OF GROUPS

Let $G$ be a group. The order graph of $G$ is the (undirected)graph $Gamma(G)$,those whose vertices are non-trivial subgroups of $G$ and two distinctvertices $H$ and $K$ are adjacent if and only if either$o(H)|o(K)$ or $o(K)|o(H)$. In this paper, we investigate theinterplay between the group-theoretic properties of $G$ and thegraph-theoretic properties of $Gamma(G)$. For a finite group$G$, we s...

متن کامل

All Ramsey Numbers r(K3, G) for Connected Graphs of Order 7 and 8

In this paper we will give all Ramsey numbers r(K 3 ; G) for connected graphs G of order 7 and 8. For smaller orders and not connected graphs of order up to 8, the number of graphs with given Ramsey number is listed for all possible values.

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:
  • CoRR

دوره abs/1203.6536  شماره 

صفحات  -

تاریخ انتشار 2011