A new bound of radius with irregularity index
Küçük Resim Yok
Tarih
2013
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
ELSEVIER SCIENCE INC
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this paper, we use a technique introduced in the paper [P. Dankelmann, R. C. Entringer, Average distance, minimum degree and spanning trees, J. Graph Theory 33 (2000), 1-13] to obtain a strengthening of an old classical theorem by Erdos et al. [P. Erdos, J. Pach, R. Pollack, Z. Tuza, Radius, diameter, and minimum degree, J. Combin. Theory B 47 (1989), 73-79] on radius and minimum degree. To be more detailed, we will prove that if G is a connected graph of order n with the minimum degree delta, then the radius G does not exceed 3/2(n - t + 1/delta + 1 + 1) where t is the irregularity index (that is the number of distinct terms of the degree sequence of G) which has been recently defined in the paper [S. Mukwembi, A note on diameter and the degree sequence of a graph, Appl. Math. Lett. 25 (2012), 175-178]. We claim that our result represent the tightest bound that ever been obtained until now. (C) 2012 Elsevier Inc. All rights reserved.
Açıklama
Anahtar Kelimeler
Bounds, Irregularity index, Minimum degree, Radius
Kaynak
APPLIED MATHEMATICS AND COMPUTATION
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
219
Sayı
11
