论文标题
在签名的图形上，光谱半径不超过$ \ sqrt {2+ \ sqrt {5}} $
On signed graphs whose spectral radius does not exceed $\sqrt{2+\sqrt{5}}$
论文作者
论文摘要
Hoffman程序在与图$ G $相关的任何真实或复杂的方形矩阵$ M $方面，源于霍夫曼在图形邻接矩阵的光谱上的限制点的开创性工作，均未超过$ \ sqrt {2+ \ sqrt {2+\ sqrt {5}} $。签名的图形$ \ dot {g} =（g，σ）$是$（g，σ），$ g =（v，e）$是一个简单的图形，$σ：e（g）\ rightarrow \ rightarrow \ {+{+{+1，-1，-1 \} $是符号功能。在本文中，我们研究了霍夫曼签名图的计划。在这里，将标识所有符号半径的签名图，其光谱半径不超过$ \ sqrt {2+ \ sqrt {5}} $。
The Hoffman program with respect to any real or complex square matrix $M$ associated to a graph $G$ stems from Hoffman's pioneering work on the limit points for the spectral radius of adjacency matrices of graphs does not exceed $\sqrt{2+\sqrt{5}}$. A signed graph $\dot{G}=(G,σ)$ is a pair $(G,σ),$ where $G=(V,E)$ is a simple graph and $σ: E(G)\rightarrow \{+1,-1\}$ is the sign function. In this paper, we study the Hoffman program of signed graphs. Here, all signed graphs whose spectral radius does not exceed $\sqrt{2+\sqrt{5}}$ will be identified.
