Stephen C. Newman

Classical Galois Theory

• Gebundenes Buch

Produktbeschreibung

With a focus on one central theme (the Impossibility Theorem) throughout, this highly accessible introduction to Galois theory presents a classical treatment of the topic and poses questions related to the solvability of polynomial equations by radicals. Modern points of view are also discussed in contrast to the historical development and context. With exercises for each chapter, as well as useful appendices, this guide is ideal for anyone wanting a deeper appreciation of the origins of Galois theory, its fundamental concepts, and applications.

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Explore the foundations and modern applications of Galois theory

Galois theory is widely regarded as one of the most elegant areas of mathematics. A Classical Introduction to Galois Theory develops the topic from a historical perspective, with an emphasis on the solvability of polynomials by radicals. The book provides a gradual transition from the computational methods typical of early literature on the subject to the more abstract approach that characterizes most contemporary expositions.

The author provides an easily-accessible presentation of fundamental notions such as roots of unity, minimal polynomials, primitive elements, radical extensions, fixed fields, groups of automorphisms, and solvable series. As a result, their role in modern treatments of Galois theory is clearly illuminated for readers. Classical theorems by Abel, Galois, Gauss, Kronecker, Lagrange, and Ruffini are presented, and the power of Galois theory as both a theoretical and computational tool is illustrated through:
A study of the solvability of polynomials of prime degree
Development of the theory of periods of roots of unity
Derivation of the classical formulas for solving general quadratic, cubic, and quartic polynomials by radicals

Throughout the book, key theorems are proved in two ways, once using a classical approach and then again utilizing modern methods. Numerous worked examples showcase the discussed techniques, and background material on groups and fields is provided, supplying readers with a self-contained discussion of the topic.

A Classical Introduction to Galois Theory is an excellent resource for courses on abstract algebra at the upper-undergraduate level. The book is also appealing to anyone interested in understanding the origins of Galois theory, why it was created, and how it has evolved into the discipline it is today.

Produktdetails

• Verlag: Wiley & Sons
• 1. Auflage
• Seitenzahl: 296
• Erscheinungstermin: 17. Juli 2012
• Englisch
• Abmessung: 240mm x 161mm x 21mm
• Gewicht: 616g
• ISBN-13: 9781118091395
• ISBN-10: 1118091396
• Artikelnr.: 35062732

Autorenporträt

Kurt's professional journey spans continents and industries, with a proven record of delivering outstanding results for companies ranging from small enterprises to multinational organisations across Australia, the Middle East, Europe, and Asia. His strategic ability has consistently driven sales revenue growth, achieving remarkable increases ranging from 10% to 56%.Recognized as a sales expert, Kurt has achieved major sales awards across five distinct industries. His capability extends to different sales environments, encompassing new product sales; consultative sales; relationship-driven sales, and the competitive field of retail. In the year 2000, Kurt established Sales Consultants an organisation committed to improving sales performance for its client organisations. To share his wisdom, he has written over 80 sales articles that resonate with both his social media followers and readers of traditional media publications. Kurt is the author of 21 Timeless Insights for Sales Success. His latest book, The Most Unlikely Salesperson has attracted comments including 'engaging' 'relatable' 'insightful' 'practical' and 'funny'. This one-of-a-kind book is a narrative on actual sales and sales strategy situations from retail to board of directors, tangible to intangible products and services.Kurt's commitment to lifelong learning is exemplary, having pursued part-time studies for over two decades to deepen his understanding of business dynamics, and human behaviour. He was the Founding Director and Chair of the Southern Highlands Chamber of Commerce and Industry Ltd. Under his visionary leadership, the organisation achieved the prestigious State Chamber of the Year award in 2015 outperforming 270 chambers. A new benchmark was created by being the first business chamber to achieve the award in less than 2 years.

Inhaltsangabe

PREFACE xi 1 CLASSICAL FORMULAS 1 1.1 Quadratic Polynomials
3 1.2 Cubic Polynomials
5 1.3 Quartic Polynomials
11 2 POLYNOMIALS AND FIELD THEORY 15 2.1 Divisibility
16 2.2 Algebraic Extensions
24 2.3 Degree of Extensions
25 2.4 Derivatives
29 2.5 Primitive Element Theorem
30 2.6 Isomorphism Extension Theorem and Splitting Fields
35 3 FUNDAMENTAL THEOREM ON SYMMETRIC POLYNOMIALS AND DISCRIMINANTS 41 3.1 Fundamental Theorem on Symmetric Polynomials
41 3.2 Fundamental Theorem on Symmetric Rational Functions
48 3.3 Some Identities Based on Elementary Symmetric Polynomials
50 3.4 Discriminants
53 3.5 Discriminants and Subfields of the Real Numbers
60 4 IRREDUCIBILITY AND FACTORIZATION 65 4.1 Irreducibility Over the Rational Numbers
65 4.2 Irreducibility and Splitting Fields
69 4.3 Factorization and Adjunction
72 5 ROOTS OF UNITY AND CYCLOTOMIC POLYNOMIALS 80 5.1 Roots of Unity
80 5.2 Cyclotomic Polynomials
82 6 RADICAL EXTENSIONS AND SOLVABILITY BY RADICALS 89 6.1 Basic Results on Radical Extensions
89 6.2 Gauss's Theorem on Cyclotomic Polynomials
93 6.3 Abel's Theorem on Radical Extensions
104 6.4 Polynomials of Prime Degree
109 7 GENERAL POLYNOMIALS AND THE BEGINNINGS OF GALOIS THEORY 117 7.1 General Polynomials
117 7.2 The Beginnings of Galois Theory
124 8 CLASSICAL GALOIS THEORY ACCORDING TO GALOIS 135 9 MODERN GALOIS THEORY 151 9.1 Galois Theory and Finite Extensions
152 9.2 Galois Theory and Splitting Fields
156 10 CYCLIC EXTENSIONS AND CYCLOTOMIC FIELDS 171 10.1 Cyclic Extensions
171 10.2 Cyclotomic Fields
179 11 GALOIS'S CRITERION FOR SOLVABILITY OF POLYNOMIALS BY RADICALS 185 12 POLYNOMIALS OF PRIME DEGREE 192 13 PERIODS OF ROOTS OF UNITY 200 14 DENESTING RADICALS 225 15 CLASSICAL FORMULAS REVISITED 231 15.1 General Quadratic Polynomial
231 15.2 General Cubic Polynomial
233 15.3 General Quartic Polynomial
236 APPENDIX A COSETS AND GROUP ACTIONS 245 APPENDIX B CYCLIC GROUPS 249 APPENDIX C SOLVABLE GROUPS 254 APPENDIX D PERMUTATION GROUPS 261 APPENDIX E FINITE FIELDS AND NUMBER THEORY 270 APPENDIX F FURTHER READING 274 REFERENCES 277 INDEX 281