Abstract:
Given two graphs
G
and
H
, the Ramsey number
R(G,H)
is the smallest positive integer
N
such that every 2-coloring of the edges of
K_N
contains either a red
G
or a blue
H
. Let
K_N-1\sqcup K_1,\,k
be the graph obtained from
K_N-1
by adding a new vertex
v
connecting
k
vertices of
K_N-1
. A graph
G
with
\chi(G)=k+1
is called edge-critical if
G
contains an edge
e
such that
\chi(G-e)=k
. A considerable amount of research has been conducted by previous scholars on Ramsey numbers of graphs. In this study, we show that for an edge-critical graph
G
with
\chi(G)=k+1
, when
k\geq 2
,
t\geq 2
, and
n
is sufficiently large,
R(G, K_1+nK_t)=knt+1
and
r_*(G,K_1+nK_t)=(k-1)nt+t
.