Group Theory is intended as a textbook for a one-term course in group theory for senior undergraduate or graduate students. It provides students with good insight into group theory as quickly as possible. Simplicity and working knowledge are emphasized here over mathematical completeness. This book will provide a rigorous proof-based modern treatment of the main results of group theory. As a result, proofs are in great details with a lot of interesting examples.This book can also serve as a reference for professional mathematicians. The book contains 221 carefully selected exercises of varying difficulty which will allow students to practice their own computational and proof-writing skills. Sample solutions to some exercise questions are provided, from which students can learn to write their own solutions and proofs. Besides standard ones, many of the exercises are very interesting.

Group Theory includes:



basic properties of groups
symmetric groups and alternating groups
isomorphism theorems, commutator subgroups, direct and semi-direct products of groups
group action on sets, Cauchy-Frobenius Lemma, symmetries of the regular polyhedrons
Jordan-Holder Theorem and Sylow Theorems
free groups, group presentations, finitely generated abelian groups
solvable groups, Hall subgroups, characteristically simple groups, Sylow systems and Sylow bases
nilpotent groups, Frattini subgroups
basic properties of representations of groups on vector spaces, subrepresentations; irreducibility, Schur's Lemma, and Maschke's Theorem