Author/Authors :
Nikiforov، نويسنده , , Vladimir، نويسنده ,
Abstract :
In this note we complete an investigation started by Erdős in 1963 that aims to find the strongest possible conclusion from the hypothesis of Turán’s theorem in extremal graph theory.
r + ( s 1 , … , s r ) be the complete r -partite graph with parts of sizes s 1 ≥ 2 , s 2 , … , s r with an edge added to the first part. Letting t r ( n ) be the number of edges of the r -partite Turán graph of order n , we prove that:
l r ≥ 2 and all sufficiently small c > 0 , every graph of sufficiently large order n with t r ( n ) + 1 edges contains a K r + ( ⌊ c ln n ⌋ , … , ⌊ c ln n ⌋ , ⌈ n 1 − c ⌉ ) .
o give a corresponding stability theorem and two supporting results of wider scope.
Keywords :
clique , stability , r -partite subgraph , Tur?n’s theorem