2nd Kindai Workshop

Multiple Zeta Values and
Modular Forms

Date: November 8th - 10th, 2024
Venue: Kindai University, Osaka, Japan

Description

Multiple zeta values and modular forms are important research subjects that appear in various fields of mathematics and mathematical physics. Since the discovery of mysterious phenomena describing their relationships in the 1990s, there has been significant development in fusion theories, such as multiple Eisenstein series, elliptic multiple zeta values, q-analogues and multiple modular values, aimed at elucidating these phenomena over the past decade. This project aims to promote international exchange and intensive research among young researchers in this field by inviting several researchers from both domestic and international institutions, providing opportunities for a one-week research stay at Kindai University, including a three-day workshop.

In this workshop, we will have invited talks by senior researchers and international presentations by young researchers on topics related to multiple zeta values and modular forms. Besides the talks, we plan to have a speed talk session where we particularly encourage young students (e.g., master's students) to give a short introduction (around 5 minutes) on their current research projects. With this, we want to encourage interaction among the participants.


Notice for Participants

Pre-registration for the workshop is not required. However, if you fall under any of the following categories, please register using the Google Form (the deadline is October 31st):

  • Participants who wish to attend the banquet at Izakaya きらくや五十鈴 on November 8th.
  • Participants, especially, of students who would like to give a Speedtalk (due to a high number of applicants, some submissions may not be accepted). (All available slots have been filled (Oct. 18th))
  • Participants who wish to use the on-campus accommodations (the cost ranges 3,000 ~ 5,000 yen per night). Please note that availability is limited and will be on a first-come, first-served basis. (Fully booked!)


Sponsorship

The workshop is supported by JSPS KAKENHI Grant Number 23K03034 and the Japan Tourism Agency's "Project to Promote the Attraction and Hosting of International Conferences at Universities".


Access Information

Access to Kindai University; English, 日本語

Invited Speakers

Francis Brown (University of Oxford)
Annika Burmester (Bielefeld University / Nagoya University)
Minoru Hirose (Kagoshima University)
Hayato Kanno (Tohoku University)
Katsumi Kina (Kyushu University)
Erik Panzer (University of Oxford)
Jean-Luc Portner (University of Oxford)
Kenji Sakugawa (Shinshu University)
Jinbo Yu (Nagoya University)

Speakers of SpeedTalk

Ku-Yu Fan (Nagoya University)
Francis Atta Howard (CIPMA-UNESCO)
Hanamichi Kawamura (Tokyo University of Science)
Takumi Maesaka (Kyushu University)
Risan (Nagoya University)
Jianbo Sun (Kyushu University)
Yuto Tsuruta (Tohoku University)
Mahiro Yokomizo (Tohoku University)

Program (tentative)
Friday (8th) @ Building 31 Saturday (9th) @ Building 3 Sunday (10th) @ Building 3
10:00 -- 12:00
Free discussion
10:00 -- 11:00 @ 3-304
Minoru Hirose (Kagoshima Univ.)
Cyclotomic multiple zeta values of level \(2^n\) or \(3^n\)
10:00 -- 11:00 @ 3-304
Annika Burmester (Nagoya Univ.)
Algebraic relations between multiple Eisenstein series
Abstract: In 2006, Gangl, Kaneko, and Zagier introduced multiple Eisenstein series as a generalization of classical Eisenstein series. Their constant Fourier coefficients are multiple zeta values, offering deeper insights into the relationship between these two types of objects. We want to describe the rational algebraic relations among multiple Eisenstein series. As a first step, we introduce a combinatorial version of them, which is essentially constructed by replacing the Fourier coefficients by a rational solution of the double shuffle relations. Inspired by Racinet’s work on formal multiple zeta values, we study the relations among combinatorial multiple Eisenstein series modulo products in terms of non-commutative polynomials. Precisely, we present a vector space bm_0 extending Racinet’s double shuffle Lie algebra dm_0. We propose a Lie bracket on bm_0, derived from a post-Lie structure and generalizing the Ihara bracket.
11:20 -- 12:00 @ 3-304
Jean-Luc Portner (Univ. of Oxford)
Associators and single-valued multiple zeta values
11:20 -- 12:00 @ 3-304
Katsumi Kina (Kyushu Univ.)
Properties of Formal Double Zeta Values of Level N
12:00 -- 13:30
Lunch break
12:00 -- 13:30
Lunch break
12:00 -- 13:30
Lunch break
13:30 -- 14:30
Free discussion
13:30 -- 14:30 @ 3-304
Erik Panzer (Univ. of Oxford)
Combinatorial Feynman integrals and Apery limits
13:30 -- 20:00
Free discussion
15:00 -- 16:00 @ 31-802
Kenji Sakugawa (Shinshu Univ.)
On mixed Hodge structures on prounipotent fundamental groups of modular curves
14:50 -- 15:30 @ 3-304
Hayato Kanno (Tohoku Univ.)
On a connection between multiple Eisenstein series of level N and Goncharov's coproduct
16:10 -- 16:30 @ 31-802
Speed Talk Session 1

Sun Jianbo (Kyushu Univ.): Sum formula for double Eisenstein series (slides)

Risan (Nagoya Univ.): Formal finite multiple zeta values and modular forms (slides)

Yuto Tsuruta (Tohoku Univ.): \(\sum\) and \(\int\)-discretization, \(q\)-analogues, and related topics (slides)

Hanamichi Kawamura (Tokyo Univ. of Science): Central corrections on dimorphic groups (slides)
15:40 -- 16:00 @ 3-304
Speed Talk Session 2

Ku-Yu Fan (Nagoya Univ.): Coaction Formula for the motivic version of Yamamoto's integral (slides)

Takumi Maesaka (Kyushu Univ.): On evaluations of multiple zeta-star values of Bowman-Bradley type (slides)

Mahiro Yokomizo (Tohoku Univ.): Manin’s iterated integrals and multiple Hecke L-functions (slides)

Francis Atta Howard (CIPMA-UNESCO): \(p\)-sequence ordering of the multiple zeta values (slides)
16:45 -- 17:45* @ 31-802
Francis Brown (Univ. of Oxford)
Galois theory for multiple zeta values and other transcendental numbers
Based on the example of multiple zeta values, which have a very intricate algebraic structure first investigated by Euler, I will explain how to set up a surprisingly rich Galois theory' of multiple zeta values which builds on ideas of Grothendieck. It takes the form of a group of symmetries which acts on multiple zeta values, preserving all the known algebraic relations. In fact, this phenomenon holds for very general classes of transcendental numbers and gives a completely new way to think about different parts of mathematics and physics. Examples include: elliptic integrals, beta and hypergeometric functions, and Feynman integrals in quantum field theory.
16:20 -- 17:00 @ 3-304
Jinbo Yu (Nagoya Univ.)
Schur multiple Eisenstein series
19:00 -- 21:00 @ きらくや五十鈴
Banquet
* ... A co-hosting of Math Colloquium at Kindai University.