{"title":"On the skew spectral moments of graphs","authors":"F. Taghvaee, G. Fath-Tabar","doi":"10.22108/TOC.2017.20737","DOIUrl":null,"url":null,"abstract":"Let $G$ be a simple graph, and $G^{sigma}$ be an oriented graph of $G$ with the orientation $sigma$ and skew-adjacency matrix $S(G^{sigma})$. The $k-$th skew spectral moment of $G^{sigma}$, denoted by $T_k(G^{sigma})$, is defined as $sum_{i=1}^{n}( lambda_{i})^{k}$, where $lambda_{1}, lambda_{2},cdots, lambda_{n}$ are the eigenvalues of $G^{sigma}$. Suppose $G^{sigma_1}_{1}$ and $G^{sigma_2}_{2}$ are two digraphs. If there exists an integer $k$, $1 leq k leq n-1$, such that for each $i$, $0 leq i leq k-1$, $T_i(G^{sigma_1}_{1}) = T_i(G^{sigma_2}_{2})$ and $T_k(G^{sigma_1}_{1}) <T_k(G^{sigma_ 2}_{2})$ then we write $G^{sigma_1}_{1} prec_{T} G^{sigma_2}_{2}$. In this paper, we determine some of the skew spectral moments of oriented graphs. Also we order some oriented unicyclic graphs with respect to skew spectral moment.","PeriodicalId":43837,"journal":{"name":"Transactions on Combinatorics","volume":"6 1","pages":"47-54"},"PeriodicalIF":0.6000,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Transactions on Combinatorics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.22108/TOC.2017.20737","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Let $G$ be a simple graph, and $G^{sigma}$ be an oriented graph of $G$ with the orientation $sigma$ and skew-adjacency matrix $S(G^{sigma})$. The $k-$th skew spectral moment of $G^{sigma}$, denoted by $T_k(G^{sigma})$, is defined as $sum_{i=1}^{n}( lambda_{i})^{k}$, where $lambda_{1}, lambda_{2},cdots, lambda_{n}$ are the eigenvalues of $G^{sigma}$. Suppose $G^{sigma_1}_{1}$ and $G^{sigma_2}_{2}$ are two digraphs. If there exists an integer $k$, $1 leq k leq n-1$, such that for each $i$, $0 leq i leq k-1$, $T_i(G^{sigma_1}_{1}) = T_i(G^{sigma_2}_{2})$ and $T_k(G^{sigma_1}_{1})