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2025 (Current Year) Faculty Courses School of Science Department of Physics Graduate major in Physics

Advanced Special Lectures in Physics VI

Academic unit or major
Graduate major in Physics
Instructor(s)
Yasuaki Hikida
Class Format
Lecture
Media-enhanced courses
-
Day of week/Period
(Classrooms)
Intensive
Class
-
Course Code
PHY.T635
Number of credits
100
Course offered
2025
Offered quarter
2Q
Syllabus updated
Jul 2, 2025
Language
English

Syllabus

Course overview and goals

In the path integral formulation of quantum theory, complexifying the integration contour can sometimes render the integral convergent. When this idea is applied to quantum gravity, complexified geometries emerge as saddle points.
A well-known example of such complexified geometry appears in the context of the no-boundary proposal for the creation of the universe from "nothing." The choice of integration contour ultimately reduces to the question of which geometries are physically realized.
In recent years, intensive research on admissible complexified geometries
has been conducted by Kontsevich, Segal, Witten, and others.
This course aims to explain these developments and introduce related research based on the gauge/gravity correspondence.

Course description and aims

To understand the general framework of path complexification in the path integral formulation of quantum theory.
To deepen insight into the issues that arise when this idea is applied to quantum gravity, and how these issues may be resolved.

Keywords

path integral, complexified geometries, gauge/gravity correspondence

Competencies

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

Class flow

The lecture is given in a form of intensive course in English.
Scheduled on 9/8(Mon), 9/9(Tue), 9/10(Wed).

Course schedule/Objectives

Course schedule Objectives
Class 1 Path integrals and the method of complexification To be specified during the lecture
Class 2 Complexification in geometry To be specified during the lecture
Class 3 Concrete examples of complexified geometry To be specified during the lecture
Class 4 Concrete examples of complexified geometry To be specified during the lecture
Class 5 Complex saddles in Liouville theory To be specified during the lecture
Class 6 Analytic continuation and the Stokes phenomenon To be specified during the lecture
Class 7 Complexified geometry via gauge/gravity correspondence To be specified during the lecture

Study advice (preparation and review)

Textbook(s)

Unspecified

Reference books, course materials, etc.

Unspecified

Evaluation methods and criteria

Evaluation will be based on a report.

Related courses

  • PHY.Q433 : Field Theory I

Prerequisites

None

Other

This is a second-quarter course; however, as it will be conducted during the summer vacation, the reporting of grades will be delayed. Please be aware that the grades will not be submitted in time for the September graduation assessment.