Showing papers by "Huiqiu Lin published in 2020"
TL;DR: This work obtains the exact value of e x s p ( n, C 6 ) and characterize the unique extremal graph and confirms Nikiforov’s conjecture on the spectral radius of graphs without paths and cycles of specified length for k = 2.
42 citations
TL;DR: The Nordhaus–Gaddum type bounds for the Aα-spectral radius are considered and the largest eigenvalue of Aα(G) is determined.
16 citations
TL;DR: Bapat and Sivasubramanian as mentioned in this paper gave an upper bound for the second largest distance eigenvalue of a uniform block graph, which they used to determine all block graphs whose second largest eigenvalues are at most − 1 2.
7 citations
Posted Content•
TL;DR: The maximum (signless Laplacian) spectral radius of a wheel-free graph of order $n$ is determined, and the extremal graphs are characterized.
Abstract: A wheel graph is a graph formed by connecting a single vertex to all vertices of a cycle. A graph is called wheel-free if it does not contain any wheel graph as a subgraph. In 2010, Nikiforov proposed a Brualdi-Solheid-Turan type problem: what is the maximum spectral radius of a graph of order $n$ that does not contain subgraphs of particular kind. In this paper, we study the Brualdi-Solheid-Turan type problem for wheel-free graphs, and we determine the maximum (signless Laplacian) spectral radius of a wheel-free graph of order $n$. Furthermore, we characterize the extremal graphs.
6 citations
TL;DR: By using majorization, it is shown that some graphs are determined by their A α -spectra, and that the lollipop graph is determined by its Aα -spectrum for 0 α 1.
4 citations
TL;DR: In this paper, the maximum number of nonzero entries in k-idempotent 0-1 matrices of a given order as well as the k-empotent matrices attaining this maximum number were determined.
3 citations
TL;DR: In this article, all connected graphs with three distinct signless Laplacian eigenvalues of which the second one is at most five are determined and the third one is unknown.
Abstract: In this paper, all connected graphs with three distinct signless Laplacian eigenvalues of which the second one is at most five are determined.
3 citations