The classical spectral Turán problem is to determine the maximum spectral radius of an -free graph of order . Let be the set of all unbalanced . Wang, Hou and Li and Chen and Yuan studied the existence of unbalanced and , respectively. In this paper, we focus on the spectral Turán problem of -free signed graph for . By using a different method, we give an answer for and completely characterize the corresponding extremal signed graph.

中文翻译：

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[公式省略]无符号图的谱图兰问题

经典谱图兰问题是确定 阶自由图的最大谱半径。让 为所有不平衡的集合。 Wang、Hou 和 Li 以及 Chen 和 Yuan 分别研究了不平衡 和 的存在性。在本文中，我们重点研究 的 -free 有符号图的谱 Turán 问题。通过使用不同的方法，我们给出了相应的极值符号图的答案并完整地表征了该图。