# Gwybodaeth Modiwlau

Module Identifier
MA30110
Module Title
Group Theory
2014/2015
Co-ordinator
Semester
Semester 1
Pre-Requisite
Other Staff

#### Course Delivery

Delivery Type Delivery length / details
Lecture 19 Hours. (19 x 1 hour lectures)
Seminars / Tutorials 3 Hours. (3 x 1 hour examples classes)

#### Assessment

Assessment Type Assessment length / details Proportion
Semester Exam 2 Hours   (written examination)  100%
Supplementary Exam 2 Hours   (written examination)  100%

### Learning Outcomes

On completion of this module, a student should be able to:
1. determine whether given algebraic systems are groups;
2. determine whether elements and subsets of a group possess a variety of properties;
3. state and prove some fundamental theorems, selected from the isomorphism theorems, the orbit-stabilizer theorem and the theorems of Lagrange, Cayley and Sylow;
4. represent groups as matrix groups, as permutation groups and with generator-relation presentations, and use these representations to compute within the groups;
5. solve problems in group theory by selecting and applying appropriate theorems and techniques from the general theory.

### Brief description

The concept of a group occurs naturally in situations involving symmetry or in which some quantity is being preserved; for example, various letters such as A, S and I possess different numbers of symmetries and rigid motions preserve distance. This module will introduce the notion of a group as an algebraic object defined by a simple set of axioms. Various techniques for describing groups (presentations, matrix and permutation representation) will be studied. The principal structure theorems for finite groups will be described and applied in a variety of group theoretic contexts.

### Aims

To provide a deeper understanding of the concepts and techniques of abstract algebra, introduced in module MA20310, by focusing on the group concept, starting with an axiomatic development of group theory, establishing a structure theory, mainly in the context of finite groups, and giving brief illustrations of a selection of applications of group theory.

### Content

1. Fundamentals: Definitions and examples. Presentations of groups. Elementary consequences of the definitions. Subgroups. cosets. Lagrange's theorem.
2. Basic structure theory: Normal subgroups and factor groups. Direct products. Homomorphisms. The isomorphism theorems. Automorphism groups.
3. Permutation groups: Symmetric groups. Cycle decomposition. Regular representation. Cayley's theorem. Orbits. Stabilizers. The orbit-stabilizer theorem.
4. Local structure theory: p-subgroups. The Sylow theorems. Classifying groups of small order.
5. Global structure theory: Classification of finite Abelian groups. The Jordan-Holder theorem.