The signature of k-cyclic graphs of ∞-type
Let be a simple graph with vertex set and edge set . The signature of is the difference between the number of positive eigenvalues and the number of negative eigenvalues of the adjacency matrix . In [22, Linear Algebra Appl. 2013;438:331-341], it was conjectured that , where denotes the number of cy...
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Published in | Linear & multilinear algebra Vol. 64; no. 3; pp. 375 - 382 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Abingdon
Taylor & Francis
03.03.2016
Taylor & Francis Ltd |
Subjects | |
Online Access | Get full text |
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Summary: | Let
be a simple graph with vertex set
and edge set
. The signature
of
is the difference between the number of positive eigenvalues and the number of negative eigenvalues of the adjacency matrix
. In [22, Linear Algebra Appl. 2013;438:331-341], it was conjectured that
, where
denotes the number of cycles in
of length
, and
denotes the number of cycles in
of length
. The authors of this paper have established the conjecture for trees, unicyclic graphs and bicyclic graphs. We prove the conjecture for
-cyclic graphs of
-type, that is, the graphs
in which
and in which no two cycles have a common vertex. |
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ISSN: | 0308-1087 1563-5139 |
DOI: | 10.1080/03081087.2015.1041708 |