This book is concerned with results in graph theory in which linear algebra and
matrix theory play an important role. Although it is generally accepted that linear
algebra can be an important component in the study of graphs, traditionally, graph
theorists have remained by and large less than enthusiastic about using linear algebra.
The results discussed here are usually treated under algebraic graph theory, as
outlined in the classic books by Biggs  and by Godsil and Royle . Our emphasis
on matrix techniques is even gre
ater than what is found in these and perhaps
the subject matter discussed here might be termed linear algebraic graph theory to
highlight this aspect.