The main theme of this course is Galois Theory, based on the theory of finite field extensions, and its various applications. Galois Theory is one of the most important theories in modern algebra, giving foundational approach to modern mathematics, and, at the same time, one can say, one of the final subjects in the undergraduate algebra course.
In this course, we learn the basics of Galois Theory and its applications, including the solvability of algebraic equations and geometrical construction.
Students are required to learn the basics of the theory of finite field extensions, including the construction of finite extension field via the residue fields, by maximal ideals, of the polynomial ring. After learning the basics including the existence of algebraic closure of fields, we proceed to Galois Theory, such as the Galois correspondence between subgroups of the Galois group and fixed fields, of which the students are required to have good understanding. Also required is to understand its applications, such as finite fields, the solvability of algebraic equations, and geometrical construction.
Galois extension, fundamental theorem of Galois theory, finite field, solvability of algebraic equations
✔ Specialist skills | Intercultural skills | Communication skills | Critical thinking skills | Practical and/or problem-solving skills |
Standard lecture course accompanied by discussion sessions
Course schedule | Required learning | |
---|---|---|
Class 1 | introduction, notion of the field | Details will be provided during each class session |
Class 2 | extension of field | Details will be provided during each class session |
Class 3 | simple extension of field, algebraic extension of field | Details will be provided during each class session |
Class 4 | (minimal) decomposition field | Details will be provided during each class session |
Class 5 | algebraic closure of field | Details will be provided during each class session |
Class 6 | separable and inseparable entensions | Details will be provided during each class session |
Class 7 | isomorphisms of fields with their extensions | Details will be provided during each class session |
Class 8 | normal extension, Galois extension, Galois group | Details will be provided during each class session |
Class 9 | fundamental theorem of Galois Theory | Details will be provided during each class session |
Class 10 | calculations of various examples of Galois groups | Details will be provided during each class session |
Class 11 | cyclotomic field | Details will be provided during each class session |
Class 12 | trace and norm, finite field | Details will be provided during each class session |
Class 13 | cyclic Kummer extension | Details will be provided during each class session |
Class 14 | applications of the Galois Theory: solvability of algebraic equations using the roots of unity | Details will be provided during each class session |
Class 15 | applications of the Galois Theory: geometrical construction | Details will be provided during each class session |
Katsura, Toshiyuki, Algebra III, UP of Tokyo
Artin, Emile, Introduction to the Galois Theory, (Japanese translation), Chikuma Pub, 2010
Nakajima, Sho-ichi, Algebraic Equations and the Galois Theory , Kyoritsu Pub ,2006.
Final exam and discussion sessions. Details will be announced during the course.
Students are expected to have passed Algebra I and II.