The objective of the course is to explain the theory of tight closure, which is a positive-characteristic method introduced by M. Hochster and C. Huneke in 1986. This theory has been developing in connection with the studying of singularities on algebraic varieties and offers powerful tools to solve outstanding problems in commutative ring theory. We will also discuss more recent hot topics in this research, including perfectoid geometry and singularities appearing on local models of Shimura varieties.
1. Understand basic properties of Frobenius maps
2. Understand the relationship between tight closures and F-singularities
3. Understand the proof and the meaning of Kunz theorem
4. Understand the basics of perfectoid theory
Frobenius map, tight closure, F-regular ring, F-rational ring, F-injective ring, perfectoid ring
✔ Specialist skills | Intercultural skills | Communication skills | Critical thinking skills | Practical and/or problem-solving skills |
Standard lecture course.
Course schedule | Required learning | |
---|---|---|
Class 1 | We will discuss the following topics in the lectures. (1) Frobenius map and Frobenius functor (2) tight closure and colon ideal (3) Kunz theorem (4) F-regular, F-rational, and F-pure rings (5) Frobenius action on local cohomology (6) perfect rings and perfectoid rings (7) big Cohen-Macaulay algebra | Details will be provided during each class session. |
To enhance effective learning, students are encouraged to spend approximately 30 minutes preparing for class and another 30 minutes reviewing class content afterwards (including assignments) for each class.
They should do so by referring to textbooks and other course material.
None required.
「Cohen-Macaulay Rings」:W.Bruns and J.Herzog
「Foundations of Tight Closure Theory」:M. Hochster
「F-singularities: a commutative algebra appraoch」: L. Ma and T. Polstra
Assignments (100%).
Basic knowledge of some abstract algebra, including rings and modules, is preferable. It is recommended to take "MTH.A401" before taking the current course.