共 28 条
The number of P-vertices for acyclic matrices with given nullity
被引:0
|作者:
Du, Zhibin
[1
]
da Fonseca, Carlos M.
[2
,3
]
机构:
[1] South China Normal Univ, Sch Software, Foshan 528225, Guangdong, Peoples R China
[2] Kuwait Coll Sci & Technol, Block 4,POB 27235, Safat 13133, Kuwait
[3] Univ Deusto, Chair Computat Math, Bilbao 48007, Spain
基金:
中国博士后科学基金;
关键词:
P-vertices;
Acyclic matrices;
Trees;
Eigenvalues;
Nullity;
Continuity;
MULTIPLICITIES;
EIGENVALUES;
D O I:
10.1016/j.disc.2023.113592
中图分类号:
O1 [数学];
学科分类号:
0701 ;
070101 ;
摘要:
In this paper, we completely characterize those trees on n vertices for which there is a singular matrix with nullity k and the number of P-vertices is n - k -1 or n - k - 2. The characterization of acyclic matrices, with rank r and the number of P-vertices is r -1, or with odd rank r and the number of P-vertices is r - 2, was first investigated in Fonseca et al. (2021) [10]. Here we introduce a unified method to revisit those results, and further cover the unknown case with even rank r and the number of P-vertices being r - 2. In the end, a continuity problem is fully solved.& COPY; 2023 Elsevier B.V. All rights reserved.
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页数:17
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