Spectral extrema of graphs: Forbidden star-path forests

IF 0.7 3区数学 Q2 MATHEMATICS Discrete Mathematics Pub Date : 2025-04-01 Epub Date: 2024-12-10 DOI:10.1016/j.disc.2024.114351

Yanni Zhai , Xiying Yuan , Lihua You

引用次数: 0

Abstract

A path of order n is denoted by

P_{n}

, and a star of order n is denoted by

S_{n - 1}

. Recently, Fang and Yuan determined the Turán numbers of

k S_{ℓ - 1} \cup P_{ℓ}

k_{1} S_{2 ℓ - 1} \cup k_{2} P_{2 ℓ}

and

k S_{4} \cup 2 P_{5}

for n appropriately large. In this paper, we extend the results to the spectral counterpart. The graphs with maximum spectral radii among graphs containing no any copy of these three kinds of star-path forests are completely characterized.

查看原文

微信好友朋友圈 QQ好友复制链接

本刊更多论文

图的谱极值：禁星路森林

n阶路径记为Pn， n阶星形记为Sn−1。最近，Fang和Yuan在n适当大的条件下，确定了ks1 - 1∪P - 1， k1S2 - 1∪k2P2 - 1， kS4∪2P5的Turán个数。在本文中，我们将结果推广到光谱对应物。在不包含这三种星径林副本的图中，光谱半径最大的图被完全表征。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文去求助

来源期刊

Discrete Mathematics 数学-数学

CiteScore

1.50

自引率

12.50%

发文量

424

审稿时长

6 months

期刊介绍： Discrete Mathematics provides a common forum for significant research in many areas of discrete mathematics and combinatorics. Among the fields covered by Discrete Mathematics are graph and hypergraph theory, enumeration, coding theory, block designs, the combinatorics of partially ordered sets, extremal set theory, matroid theory, algebraic combinatorics, discrete geometry, matrices, and discrete probability theory. Items in the journal include research articles (Contributions or Notes, depending on length) and survey/expository articles (Perspectives). Efforts are made to process the submission of Notes (short articles) quickly. The Perspectives section features expository articles accessible to a broad audience that cast new light or present unifying points of view on well-known or insufficiently-known topics.

期刊最新文献

Paradoxical behavior in Collatz sequences Leaf to leaf path lengths in trees of given degree sequence Generalized snake posets, order polytopes, and lattice-point enumeration A note on the spectral radius and [a,b]-factor of graphs Construction of Hermitian self-dual constacyclic codes with square-root-like lower bounds on the minimum distances