Signed analogue of line graphs and their smallest eigenvalues
Signed analogue of line graphs and their smallest eigenvalues
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DOI:
10.1002/jgt.22699
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发表时间:
2020-03
影响因子:
0.9
通讯作者:
Alexander L. Gavrilyuk;A. Munemasa;Y. Sano;T. Taniguchi
中科院分区:
文献类型:
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作者:
Alexander L. Gavrilyuk;A. Munemasa;Y. Sano;T. Taniguchi
In this article, we show that every connected signed graph with smallest eigenvalue strictly greater than − 2 and large enough minimum degree is switching equivalent to a complete graph. This is a signed analogue of a theorem of Hoffman. The proof is based on what we call Hoffman's limit theorem which we formulate for Hermitian matrices, and also the extension of the concept of Hoffman graph and line graph for the setting of signed graphs.