Autor: Stanić, Zoran - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Perturbations in a Signed Graph and its Index
Autorzy:: Stanić, Zoran
Powiązania:: https://bibliotekanauki.pl/articles/31343791.pdf
Data publikacji:: 2018-08-01
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: signed graph
switching equivalence
index
computer search
Opis:: In this paper we consider the behaviour of the largest eigenvalue (also called the index) of signed graphs under small perturbations like adding a vertex, adding an edge or changing the sign of an edge. We also give a partial ordering of signed cacti with common underlying graph by their indices and demonstrate a general method for obtaining lower and upper bounds for the index. Finally, we provide our computational results related to the generation of small signed graphs.
Źródło:: Discussiones Mathematicae Graph Theory; 2018, 38, 3; 841-852
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: On Regular Signed Graphs with Three Eigenvalues
Autorzy:: Anđelić, Milica
Koledin, Tamara
Stanić, Zoran
Powiązania:: https://bibliotekanauki.pl/articles/31534886.pdf
Data publikacji:: 2020-05-01
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: adjacency matrix
eigenvalue
regular signed graph
signed line graph
block design
Opis:: In this paper our focus is on regular signed graphs with exactly 3 (distinct) eigenvalues. We establish certain basic results; for example, we show that they are walk-regular. We also give some constructions and determine all the signed graphs with 3 eigenvalues, under the constraint that they are either signed line graphs or have vertex degree 3. We also report our result of computer search on those with at most 10 vertices.
Źródło:: Discussiones Mathematicae Graph Theory; 2020, 40, 2; 405-416
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: More on Signed Graphs with at Most Three Eigenvalues
Autorzy:: Ramezani, Farzaneh
Rowlinson, Peter
Stanić, Zoran
Powiązania:: https://bibliotekanauki.pl/articles/32222534.pdf
Data publikacji:: 2022-11-01
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: adjacency matrix
simple eigenvalue
strongly regular signed graph
vertex-deleted subgraph
weighing matrix
association scheme
Opis:: We consider signed graphs with just 2 or 3 distinct eigenvalues, in particular (i) those with at least one simple eigenvalue, and (ii) those with vertex-deleted subgraphs which themselves have at most 3 distinct eigenvalues. We also construct new examples using weighing matrices and symmetric 3-class association schemes.
Źródło:: Discussiones Mathematicae Graph Theory; 2022, 42, 4; 1313-1331
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: Some Properties of the Eigenvalues of the Net Laplacian Matrix of a Signed Graph
Autorzy:: Stanić, Zoran
Powiązania:: https://bibliotekanauki.pl/articles/32304147.pdf
Data publikacji:: 2022-08-01
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: (net) Laplacian matrix
edge perturbations
largest eigenvalue
net-degree
Opis:: Given a signed graph $ \dot{G} $, let $ A_{ \dot{G} } $ and $ D_{\dot{G}}^\pm $ denote its standard adjacency matrix and the diagonal matrix of vertex net-degrees, respectively. The net Laplacian matrix of $ \dot{G} $ is defined to be $ N_{ \dot{G} } = D_{\dot{G}}^\pm - A_{ \dot{G} } $. In this study we give some properties of the eigenvalues of $ N_{ \dot{G} } $. In particular, we consider their behaviour under some edge perturbations, establish some relations between them and the eigenvalues of the standard Laplacian matrix and give some lower and upper bounds for the largest eigenvalue of $ N_{ \dot{G} } $.
Źródło:: Discussiones Mathematicae Graph Theory; 2022, 42, 3; 893-903
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

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