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2024 Students Enrolled in or before 2015 School of Science Mathematics

Special courses on advanced topics in Mathematics D

Academic unit or major
Mathematics
Instructor(s)
Yuta Nozaki / Takefumi Nosaka
Class Format
Lecture (Face-to-face)
Media-enhanced courses
-
Day of week/Period
(Classrooms)
Intensive
Class
-
Course Code
ZUA.E334
Number of credits
200
Course offered
2024
Offered quarter
3Q
Syllabus updated
Mar 14, 2025
Language
Japanese

Syllabus

Course overview and goals

The main theme of this lecture is to understand the structure of groups consisting of homology cylinders. A homology cylinder is a certain 3-manifold with boundary, closely related to the mapping class groups of surfaces and their subgroups known as the Torelli group. They also have connections with the homology cobordism groups defined via 4-manifolds. To investigate these topics, we will introduce the LMO functor defined by Cheptea, Habiro, and Massuyeau, and learn about its properties and applications.

As mentioned above, homology cylinders have various connections to the study of low-dimensional topology. In this lecture, we will explore important topics and fundamental research methods in low-dimensional topology among these relationships. For example, Dehn surgery on links and its special case known as clasper surgery are fundamental with many applications. Regarding the LMO functor, we will ensure a solid understanding through simple computational examples.

Course description and aims

・Be familiar with Dehn surgery on links.
・Understand a relation between the Torelli group and homology cylinders.
・Be able to compute the Kontsevich invariant and the LMO functor in lower degree.
・Understand a relation between the LMO functor and clasper surgery.
・Understand groups consisting of homology cylinders with lower degree.

Keywords

quantum topology, mapping class group, knot, homology cobordism group, Kontsevich invariant, LMO functor, clasper surgery

Competencies

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

Class flow

This is a standard lecture course. There will be some assignments.

Course schedule/Objectives

Course schedule Objectives
Class 1 The following topics will be covered in this order: ・Homology cylinders and mapping class groups ・The lower central series of the Torelli group and its graded quotients ・A category of cobordisms and that of tangles ・Jacobi diagrams and the Kontsevich invariant ・The LMO functor and clasper surgery ・Homomorphisms induced by the LMO functor ・The structure of groups related to homology cylinders to be specified in each lecture

Study advice (preparation and review)

To enhance effective learning, students are encouraged to spend approximately 100 minutes preparing for class and another 100 minutes reviewing class content afterwards (including assignments) for each class.
They should do so by referring to textbooks and other course material.

Textbook(s)

None

Reference books, course materials, etc.

T. Ohtsuki, Quantum invariants: a study of knots, 3-manifolds, and their sets, Series on Knots and Everything 29, World Sci., River Edge, NJ (2002)

Evaluation methods and criteria

Assignments (100%).

Related courses

  • MTH.B301 : Geometry I
  • MTH.B302 : Geometry II
  • MTH.B331 : Geometry III

Prerequisites

Good understanding on the materials in the "related courses" is expected

Other

Not in particular