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2026 (Current Year) Faculty Courses School of Science Department of Mathematics Graduate major in Mathematics

Advanced topics in Algebra B

Academic unit or major
Graduate major in Mathematics
Instructor(s)
Kazuma Shimomoto
Class Format
Lecture (Face-to-face)
Media-enhanced courses
-
Day of week/Period
(Classrooms)
5-6 Thu (M-102(H115))
Class
-
Course Code
MTH.A402
Number of credits
100
Course offered
2026
Offered quarter
2Q
Syllabus updated
Mar 5, 2026
Language
English

Syllabus

Course overview and goals

Building upon the material covered in 'Advanced Topics in Algebra A,' this course introduces the foundations of Almost Mathematics. Furthermore, after discussing continuous valuations, Banach rings、Tate rings, and perfectoid rings, we will provide an exposition of the Almost Purity Theorem.

Course description and aims

Students will become proficient in Almost Mathematics and the handling of perfectoid algebras via the Frobenius map. Additionally, the course aims to deepen understanding of the concept of perfectoid spaces and the tilting equivalence (tilting functor).

Keywords

Almost mathematics、Banach ring、Tate ring、perfectoid space、tilting、almost purity theorem

Competencies

  • Specialist skills
  • Intercultural skills
  • Communication skills
  • Critical thinking skills
  • Practical and/or problem-solving skills

Class flow

Standard lecture course

Course schedule/Objectives

Course schedule Objectives
Class 1

Introduction to almost mathematics

Details will be provided during each class session

Class 2

Banach ring, continuous valuation

Details will be provided during each class session

Class 3

Adic space, rational localization1

Details will be provided during each class session

Class 4

Adic space, rational localization2

Details will be provided during each class session

Class 5

Perfectoid space

Details will be provided during each class session

Class 6

Almost etale extension, tilting correspondence

Details will be provided during each class session

Class 7

Almost purity theorem

Details will be provided during each class session

Study advice (preparation and review)

To enhance effective learning, students are encouraged to explore references provided in lectures and other materials.

Textbook(s)

None required.

Reference books, course materials, etc.

M.Hochster: Foundations of tight closure theory
T.Polstra and L.Ma: F-singularities: A commutative algebra approach(https://www.math.purdue.edu/~ma326/F-singularitiesBook.pdf)
K.Shimomoto: Lectures on perfectoid geometry for commutative algbraists
O.Gabber and L.Ramero: Almost ring theory

Evaluation methods and criteria

Course scores are evaluated by homework assignments. Details will be announced during the course.

Related courses

  • MTH.A401 : Advanced topics in Algebra A
  • ZUA.A331 : Advanced courses in Algebra A
  • ZUA.A332 : Advanced courses in Algebra B

Prerequisites

MTH.A401 : Advanced topics in Algebra A

Other

None in particular.