This book gives a general introduction to the theory of representations
of algebras. It starts with examples of classification problems of
matrices under linear transformations, explaining the three common
setups: representation of quivers, modules over algebras and additive
functors over certain categories. The main part is devoted to (i) module
categories, presenting the unicity of the decomposition into
indecomposable modules, the Auslander-Reiten theory and the technique of
knitting; (ii) the use of combinatorial tools such as dimension vectors
and integral quadratic forms; and (iii) deeper theorems such as
Gabriel's Theorem, the trichotomy and the Theorem of Kac - all
accompanied by further examples.
Each section includes exercises to facilitate understanding. By keeping
the proofs as basic and comprehensible as possible and introducing the
three languages at the beginning, this book is suitable for readers from
the advanced undergraduate level onwards and enables them to consult
related, specific research articles.