Comment on 

Volume 7, article R47 (2000)

"A Turán Type Problem Concerning the Powers of the Degrees of a Graph"

Yair Caro and Raphael Yuster


Comment by the authors, August 11, 2004:

These comments are also available in postscript of pdf format.

In the original version of this paper Theorem 1.1 was mistakenly stated for all p. This was also observed by Pikhurko [Pi01] and by Schelp. The theorem is valid only in the linear, quadratic and cubic cases. Namely:

Let k > 2 be a positive integer, and let p=1,2,3. Then t_p(n,K_k)=e_p(T(n,k)), where T(n,k) is the Turán Graph.

Theorem 1.1 is sharp in the sense that for p \geq 4, t_p(n,K_k) is not obtained by the Turán graph. This can already be seen by the fact that the complete bipartite graph G=K_{\lfloor n/2-1 \rfloor, \lceil n/2+1 \rceil} has e_4(G) > e_4(T(n,3)).

A revised version of this paper addressing this comment can be found in [CaYu04].

References

[CaYu04] Y. Caro and R. Yuster, A Turán Type Problem Concerning the Powers of the Degrees of a Graph (revised) arXiv:math.CO/0401398 (2004).
[Pi01] O. Pikhurko, Remarks on a paper of Y. Caro and R. Yuster on a Turán problem arXiv:math.CO/0101235 (2001).