An introduction to the theory of graph spectra
 
 
Description:  The spectrum of a graph is defined as the spectrum of a matrix associated to the graph; in most cases it is the adjacency matrix although some other graph matrices are used. The beginnings of the theory of graph spectra are connected with the first mathematical paper in the subject, published by L. Collatz and U. Sinogowitz in 1957. The background of the subject is the Perron-Frobenius theory of non-negative matrices. Several techniques for treating graph theory problems using eigenvalues have been developed: e.g., the interlacing theorem, the use of graph eigenspaces, the star complement technique and many others. There are many connections of the theory of graph spectra with other parts of combinatorics as well as with algebra and geometry. The theory can be classified also as a part of algebraic graph theory and of algebraic combinatorics. It is very much used in theoretical chemistry but also has some relevance to other applied fields, e.g. physics, electrical engineering and computer science.
Area(s):
Date:  2005-05-17
Start Time:   14:30
Speaker:  Drago? Cvetkovic' (Faculty of Electrical Engineering, Belgrade, Serbia and Montenegro)
Place:  Sala 5.5
Research Groups: -Algebra and Combinatorics
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