Eigenvalues, Multiplicities and Graphs

Eigenvalues, Multiplicities and Graphs
Author: Charles R. Johnson
Publisher: Cambridge University Press
Total Pages: 315
Release: 2018-02-12
Genre: Mathematics
ISBN: 110709545X

This book investigates the influence of the graph of a symmetric matrix on the multiplicities of its eigenvalues.

Graphs with Eigenvalues of High Multiplicity

Graphs with Eigenvalues of High Multiplicity
Author: Casey Boyett
Publisher:
Total Pages: 141
Release: 2015
Genre: Electronic dissertations
ISBN:

Given a graph G we can form a matrix A[subscript G] indexed by the vertices of G and which encodes the edges of G. A[subscript G] is called the adjacency matrix of G. From the adjacency matrix we may find the eigenvalues. We would now like to know what information we may garner from the eigenvalues. It turns out quite a bit may be determined from the eigenvalues, collectively called the spectrum. One big question is to ask whether or not a graph can be uniquely determined by its spectrum. Much research has been done in this area, and it is conjectured that almost all graphs may in fact be determined by their spectra. This is however a difficult task. In this dissertation we look at a subset of all graphs, namely those with either -1 or 0 in their spectrum with a given multiplicity. We first show that any such graph must either be primitive in a sense, or that it is obtained from a primitive graph by an elementary operation of blowing up or splitting vertices. We then show that the set of primitive graphs is finite, for a fixed multiplicity. Lastly, we analyze graphs with -1 or 0 in their spectra with multiplicities up to 4, and show many which are uniquely determined by their spectra.

Spectra of Graphs

Spectra of Graphs
Author: Dragoš M. Cvetković
Publisher:
Total Pages: 374
Release: 1980
Genre: Mathematics
ISBN:

The theory of graph spectra can, in a way, be considered as an attempt to utilize linear algebra including, in particular, the well-developed theory of matrices for the purposes of graph theory and its applications. to the theory of matrices; on the contrary, it has its own characteristic features and specific ways of reasoning fully justifying it to be treated as a theory in its own right.

Locating Eigenvalues in Graphs

Locating Eigenvalues in Graphs
Author: Carlos Hoppen
Publisher: Springer Nature
Total Pages: 142
Release: 2022-09-21
Genre: Mathematics
ISBN: 3031116984

This book focuses on linear time eigenvalue location algorithms for graphs. This subject relates to spectral graph theory, a field that combines tools and concepts of linear algebra and combinatorics, with applications ranging from image processing and data analysis to molecular descriptors and random walks. It has attracted a lot of attention and has since emerged as an area on its own. Studies in spectral graph theory seek to determine properties of a graph through matrices associated with it. It turns out that eigenvalues and eigenvectors have surprisingly many connections with the structure of a graph. This book approaches this subject under the perspective of eigenvalue location algorithms. These are algorithms that, given a symmetric graph matrix M and a real interval I, return the number of eigenvalues of M that lie in I. Since the algorithms described here are typically very fast, they allow one to quickly approximate the value of any eigenvalue, which is a basic step in most applications of spectral graph theory. Moreover, these algorithms are convenient theoretical tools for proving bounds on eigenvalues and their multiplicities, which was quite useful to solve longstanding open problems in the area. This book brings these algorithms together, revealing how similar they are in spirit, and presents some of their main applications. This work can be of special interest to graduate students and researchers in spectral graph theory, and to any mathematician who wishes to know more about eigenvalues associated with graphs. It can also serve as a compact textbook for short courses on the topic.

Combinatorial and Graph-Theoretical Problems in Linear Algebra

Combinatorial and Graph-Theoretical Problems in Linear Algebra
Author: Richard A. Brualdi
Publisher: Springer Science & Business Media
Total Pages: 266
Release: 2012-12-06
Genre: Mathematics
ISBN: 1461383544

This IMA Volume in Mathematics and its Applications COMBINATORIAL AND GRAPH-THEORETICAL PROBLEMS IN LINEAR ALGEBRA is based on the proceedings of a workshop that was an integral part of the 1991-92 IMA program on "Applied Linear Algebra." We are grateful to Richard Brualdi, George Cybenko, Alan George, Gene Golub, Mitchell Luskin, and Paul Van Dooren for planning and implementing the year-long program. We especially thank Richard Brualdi, Shmuel Friedland, and Victor Klee for organizing this workshop and editing the proceedings. The financial support of the National Science Foundation made the workshop possible. A vner Friedman Willard Miller, Jr. PREFACE The 1991-1992 program of the Institute for Mathematics and its Applications (IMA) was Applied Linear Algebra. As part of this program, a workshop on Com binatorial and Graph-theoretical Problems in Linear Algebra was held on November 11-15, 1991. The purpose of the workshop was to bring together in an informal setting the diverse group of people who work on problems in linear algebra and matrix theory in which combinatorial or graph~theoretic analysis is a major com ponent. Many of the participants of the workshop enjoyed the hospitality of the IMA for the entire fall quarter, in which the emphasis was discrete matrix analysis.

An Introduction to the Theory of Graph Spectra

An Introduction to the Theory of Graph Spectra
Author: Dragoš Cvetković
Publisher: Cambridge University Press
Total Pages: 0
Release: 2009-10-15
Genre: Mathematics
ISBN: 9780521134088

This introductory text explores the theory of graph spectra: a topic with applications across a wide range of subjects, including computer science, quantum chemistry and electrical engineering. The spectra examined here are those of the adjacency matrix, the Seidel matrix, the Laplacian, the normalized Laplacian and the signless Laplacian of a finite simple graph. The underlying theme of the book is the relation between the eigenvalues and structure of a graph. Designed as an introductory text for graduate students, or anyone using the theory of graph spectra, this self-contained treatment assumes only a little knowledge of graph theory and linear algebra. The authors include many new developments in the field which arise as a result of rapidly expanding interest in the area. Exercises, spectral data and proofs of required results are also provided. The end-of-chapter notes serve as a practical guide to the extensive bibliography of over 500 items.

Spectra of Graphs

Spectra of Graphs
Author: Andries E. Brouwer
Publisher: Springer Science & Business Media
Total Pages: 254
Release: 2011-12-17
Genre: Mathematics
ISBN: 1461419395

This book gives an elementary treatment of the basic material about graph spectra, both for ordinary, and Laplace and Seidel spectra. The text progresses systematically, by covering standard topics before presenting some new material on trees, strongly regular graphs, two-graphs, association schemes, p-ranks of configurations and similar topics. Exercises at the end of each chapter provide practice and vary from easy yet interesting applications of the treated theory, to little excursions into related topics. Tables, references at the end of the book, an author and subject index enrich the text. Spectra of Graphs is written for researchers, teachers and graduate students interested in graph spectra. The reader is assumed to be familiar with basic linear algebra and eigenvalues, although some more advanced topics in linear algebra, like the Perron-Frobenius theorem and eigenvalue interlacing are included.

Graphs and Matrices

Graphs and Matrices
Author: Ravindra B. Bapat
Publisher: Springer
Total Pages: 197
Release: 2014-09-19
Genre: Mathematics
ISBN: 1447165691

This new edition illustrates the power of linear algebra in the study of graphs. The emphasis on matrix techniques is greater than in other texts on algebraic graph theory. Important matrices associated with graphs (for example, incidence, adjacency and Laplacian matrices) are treated in detail. Presenting a useful overview of selected topics in algebraic graph theory, early chapters of the text focus on regular graphs, algebraic connectivity, the distance matrix of a tree, and its generalized version for arbitrary graphs, known as the resistance matrix. Coverage of later topics include Laplacian eigenvalues of threshold graphs, the positive definite completion problem and matrix games based on a graph. Such an extensive coverage of the subject area provides a welcome prompt for further exploration. The inclusion of exercises enables practical learning throughout the book. In the new edition, a new chapter is added on the line graph of a tree, while some results in Chapter 6 on Perron-Frobenius theory are reorganized. Whilst this book will be invaluable to students and researchers in graph theory and combinatorial matrix theory, it will also benefit readers in the sciences and engineering.

Inequalities for Graph Eigenvalues

Inequalities for Graph Eigenvalues
Author: Zoran Stanić
Publisher: Cambridge University Press
Total Pages: 311
Release: 2015-07-23
Genre: Mathematics
ISBN: 1316395758

Written for mathematicians working with the theory of graph spectra, this book explores more than 400 inequalities for eigenvalues of the six matrices associated with finite simple graphs: the adjacency matrix, Laplacian matrix, signless Laplacian matrix, normalized Laplacian matrix, Seidel matrix, and distance matrix. The book begins with a brief survey of the main results and selected applications to related topics, including chemistry, physics, biology, computer science, and control theory. The author then proceeds to detail proofs, discussions, comparisons, examples, and exercises. Each chapter ends with a brief survey of further results. The author also points to open problems and gives ideas for further reading.

Graph Symmetry

Graph Symmetry
Author: Gena Hahn
Publisher: Springer Science & Business Media
Total Pages: 456
Release: 1997-06-30
Genre: Mathematics
ISBN: 9780792346685

The last decade has seen two parallel developments, one in computer science, the other in mathematics, both dealing with the same kind of combinatorial structures: networks with strong symmetry properties or, in graph-theoretical language, vertex-transitive graphs, in particular their prototypical examples, Cayley graphs. In the design of large interconnection networks it was realised that many of the most fre quently used models for such networks are Cayley graphs of various well-known groups. This has spawned a considerable amount of activity in the study of the combinatorial properties of such graphs. A number of symposia and congresses (such as the bi-annual IWIN, starting in 1991) bear witness to the interest of the computer science community in this subject. On the mathematical side, and independently of any interest in applications, progress in group theory has made it possible to make a realistic attempt at a complete description of vertex-transitive graphs. The classification of the finite simple groups has played an important role in this respect.