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MATH30420: Galois Theory

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Type Tied
Level 3
Credits 20
Availability Available in 2023/24
Module Cap None.
Location Durham
Department Mathematical Sciences

Prerequisites

  • Prior knowledge of Algebra at undergraduate level.

Corequisites

  • None

Excluded Combinations of Modules

  • None

Aims

  • To introduce the way in which the Galois group acts on the field extension generated by the roots of a polynomial, and to apply this to some classical ruler-and-compass problems as well as elucidating the structure of the field extension.

Content

  • Field Extensions: Algebraic and transcendental extensions, splitting field for a polynomial, normality, separability.
  • Results from Group Theory: Normal subgroups, quotients, soluble groups, isomorphism theorems.
  • Groups acting on fields: Dedekind's lemma, fixed field, Galois group of a finite extension, definition of Galois extension, fundamental theorem of Galois theory.
  • Galois Group of Polynomials: Criterion for solubility in radicals, cubics, quartics, 'general polynomial', cyclotomic polynomials.
  • Ruler and Compass Constructions: definition, criterion for constructability, impossibility of trisecting angle, etc.
  • Further Topics.

Learning Outcomes

Subject-specific Knowledge:

  • By the end of the module students will: be able to solve novel and/or complex problems in Galois Theory.
  • have a systematic and coherent understanding of theoretical mathematics in the field of Galois Theory.
  • have acquired a coherent body of knowledge of these subjects demonstrated through one or more of the following topic areas: Algebraic field extensions, properties of normality and separability.
  • Properties of Galois correspondence.
  • Criterion of solvability of polynomial equation in radicals.
  • Non-solvability of general polynomial equation in degrees > 5.
  • Classification of finite fields.
  • Construction of irreducible polynomials with coefficients in finite fields.

Subject-specific Skills:

  • In addition students will have specialised mathematical skills in the following areas which can be used in minimal guidance: Abstract reasoning.

Key Skills:

Modes of Teaching, Learning and Assessment and how these contribute to the learning outcomes of the module

  • Lectures demonstrate what is required to be learned and the application of the theory to practical examples.
  • Assignments for self-study develop problem-solving skills and enable students to test and develop their knowledge and understanding.
  • Formatively assessed assignments provide practice in the application of logic and high level of rigour as well as feedback for the students and the lecturer on students' progress.
  • The end-of-year examination assesses the knowledge acquired and the ability to solve predictable and unpredictable problems.

Teaching Methods and Learning Hours

ActivityNumberFrequencyDurationTotalMonitored
Lectures422 per week for 20 weeks and 2 in term 31 Hour42 
Problems Classes8Four in each of terms 1 and 21 Hour 8 
Preperation and Reading150 
Total200 

Summative Assessment

Component: ExaminationComponent Weighting: 100%
ElementLength / DurationElement WeightingResit Opportunity
Written examination3 Hours100 

Formative Assessment

Eight written or electronic assignments to be assessed and returned. Other assignments are set for self-study and complete solutions are made available to students.

More information

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