GLOBAL CATEGORICAL SYMMETRIES 2026

15 juin 2026, 09:00 → 3 juil. 2026, 18:00 Europe/Paris

Institut Henri Poincaré

Thematic 3-weeks programme at the Institut Henri Poincaré, Paris, June 15th to July 3rd, 2026.

Beware: It was reported to us that scammers are sending to participants fraudulent e-mails about accomodation/fees. Please be particularly cautious about e-mails not coming from the organisers nor from an @ihp.fr address. 

Abstract

Some of the most profound open problems about the physics of quantum fields – especially at strong coupling, beyond the reach of conventional techniques – are newly accessible thanks to recent developments in topological quantum field theory (TQFT). This insight comes with a dramatic evolution of the notion of symmetries in QFT: symmetries can be characterized via topological defects of various codimensions whose multidimensional fusion generalizes wildly the notion of groups to what are called categorical symmetries. This IHP program is the fourth in a series of meetings hosted at various institutes worldwide devoted to the exploration of these aspects of symmetries, the resulting mathematical structures and their physical implications, in the context of the Simons Collaboration on Global Categorical Symmetries. World-class experts in the subject will gather at IHP in an interactive setting alternating lectures and seminars aiming at nourishing collaborations and stimulate further this rapidly evolving field.

During the first week of this program we invite PhD students and postdocs to the fourth GCS summer school. Support is available for those who apply. During the second week of this program we will host the conference Symmetries 2026, an international gathering of experts where the most recent developments about this topic will be presented. The third week of this program is a smaller workshop, where groups of researchers are welcome to network and develop new projects and ideas. More information will appear on this webpage closer to the event.

 

The program unfolds over three weeks: a school, a conference, and finally a workshop.

June 15-19: GCS26 School

IHP, Amphithéâtre Hermite, Borel Building

Lecturers

Agnès Beaudry (Colorado U Boulder)

Federico Bonetti (Murcia U)

Nat Tantivasadakarn (YITP, Stony Brook U)

Tomer Schlank (Chicago U)

Yifan Wang (NYU)

June 22-26: Symmetries 26 Conference 

IHP, Amphithéâtre Hermite, Borel building

Speakers

Andrea Antinucci (Oxford U)

Lea Bottini (IHES)

Adrien Brochier (Paris Cité)

Damien Calaque (U de Montpellier)

Christian Copetti (Oxford U)

Clay Córdova (Chicago)

Arun Debray (Kentucky U)

Thibault Decoppet (Harvard U)

Lukasz Fidkowski (Seattle U)

Jonathan Heckman (UPenn)

Wenjie Ji (PI)

Anton Kapustin (Caltech)

Cameron Krulewski (DAL)

Enoch Leung (LMU)

John McGreevy (UCSD)

Lukas Müller (PI)

Nivedita (Oxford U)

Salvatore Pace (MIT - IAS)

Julio Parra-Martinez (IHES)

Brandon Rayhaun (IAS)

David Reutter (Hamburg U)

Sakura Schafer-Nameki (Oxford U)

Pelle Steffens (TUM)

Xiao-Gang Wen (MIT)

Carolyn Zhang (Harvard U)

Yunqin Zheng (KIST-UCIS)

Chenchang Zhu (Göttingen U)

June 29-July 3: GCS26 workshop

IHP, Amphithéâtre Darboux, Borel building

 

Registration is free but mandatory.
Deadline for asking financial support: February 15th, 2026. 
Financial support is limited and will be notified by March 15th, 2026. 
Places are limited.

 

Organising committee:

• Ibrahima Bah (John Hopkins University)
• Michele Del Zotto (Uppsala University) 
• Theo Johnson Freyd (Dalhousie University & Perimeter Institute) 
• Ruben Minasian (CEA Saclay)
• Claudia Scheimbauer (TU Munich)

 

Scientific committee:

• Thomas Dumitrescu (University of California Los Angeles)
• Dan Freed (University of Texas)
• Constantin Teleman (University of California Berkley)

 

Fundings: 

The program receives also support from:

Simons Collaboration on Global Categorical Symmetries

lun. 15 juin

09:00 → 10:30 Beaudry: From Stabilizer Codes to Fracton Phases of Matter

Fracton orders are quantum systems characterized by the presence of excitations with restricted mobility. Many examples are described by stabilizer codes, that is, lattice Hamiltonians constructed from commuting generalized Pauli matrices. In this lecture series, we will explore the algebraic framework for fracton phases and mutual statistics that emerges from the study of stabilizer codes.

The course will be mostly based on work of Haah and Ruba-Yang, as well as joint work with Hermele, Shirley, Wickenden and Yang.

10:30 → 11:00 Coffee break

11:00 → 12:30 Wang: Seeing through Defects in Quantum Field Theory

Defects provide powerful probes of quantum field theory. Supported on lower-dimensional subspaces, they host their own degrees of freedom, generalize ordinary local operator algebras, and exhibit novel phases connected by renormalization group flows. We will discuss modern developments in defect dynamics, focusing on their interplay with symmetries and anomalies, and explain how they encode structural information about the ambient QFT.

12:30 → 14:30 Lunch break

Lunch is not provided. Plenty of options for lunch are available nearby.

14:30 → 16:00 Wang: Seeing through Defects in Quantum Field Theory

Defects provide powerful probes of quantum field theory. Supported on lower-dimensional subspaces, they host their own degrees of freedom, generalize ordinary local operator algebras, and exhibit novel phases connected by renormalization group flows. We will discuss modern developments in defect dynamics, focusing on their interplay with symmetries and anomalies, and explain how they encode structural information about the ambient QFT.

mar. 16 juin

09:00 → 10:30 Beaudry: From Stabilizer Codes to Fracton Phases of Matter

Fracton orders are quantum systems characterized by the presence of excitations with restricted mobility. Many examples are described by stabilizer codes, that is, lattice Hamiltonians constructed from commuting generalized Pauli matrices. In this lecture series, we will explore the algebraic framework for fracton phases and mutual statistics that emerges from the study of stabilizer codes.

The course will be mostly based on work of Haah and Ruba-Yang, as well as joint work with Hermele, Shirley, Wickenden and Yang.

10:30 → 11:00 Coffee break

11:00 → 12:30 Wang: Seeing through Defects in Quantum Field Theory

Defects provide powerful probes of quantum field theory. Supported on lower-dimensional subspaces, they host their own degrees of freedom, generalize ordinary local operator algebras, and exhibit novel phases connected by renormalization group flows. We will discuss modern developments in defect dynamics, focusing on their interplay with symmetries and anomalies, and explain how they encode structural information about the ambient QFT.

12:30 → 14:30 Lunch break

Lunch is not provided. Plenty of options for lunch are available nearby.

14:30 → 16:00 Tantivasadakarn: Symmetries and their gauging on the lattice

Much progress of generalized symmetries has been formulated in the continuum. However, on the lattice, symmetries can behave quite differently, and its fundamental organizing principles are still in development. I will give a broad introduction to symmetries on the lattice and how to gauge them. Time permitting, I will discuss subtleties in matching symmetries on the lattice to those in the continuum.

mer. 17 juin

09:00 → 10:30 Beaudry: From Stabilizer Codes to Fracton Phases of Matter

Fracton orders are quantum systems characterized by the presence of excitations with restricted mobility. Many examples are described by stabilizer codes, that is, lattice Hamiltonians constructed from commuting generalized Pauli matrices. In this lecture series, we will explore the algebraic framework for fracton phases and mutual statistics that emerges from the study of stabilizer codes.

The course will be mostly based on work of Haah and Ruba-Yang, as well as joint work with Hermele, Shirley, Wickenden and Yang.

10:30 → 11:00 Coffee break

11:00 → 12:30 Schlank

12:30 → 14:30 Lunch break

Lunch is not provided. Plenty of options for lunch are available nearby.

14:30 → 16:00 Bonetti: Aspects of SymTFT and Continuous Symmetries

In the modern perspective, the generalized global symmetries of a quantum field theory (QFT) are encoded in the spectrum of its (extended) topological operators. Finite symmetries, in particular, are expected to be captured by higher fusion categories. The Symmetry Topological Field Theory (SymTFT) provides a powerful framework for analyzing many facets of these symmetry structures.

While categorical methods and SymTFT techniques are by now well established for finite symmetries, a complete and systematic framework for continuous symmetries is still being developed. In these lectures, I will present some features of SymTFTs for continuous symmetries from a physicist’s perspective. As a complementary approach to better understanding the properties of symmetry operators associated with continuous symmetries, I will also discuss aspects of their realization in holography and string theory.

16:00 → 18:00 Poster session + Coffee break

18:30 → 21:00 Reception

jeu. 18 juin

09:00 → 10:30 Tantivasadakarn: Symmetries and their gauging on the lattice

Much progress of generalized symmetries has been formulated in the continuum. However, on the lattice, symmetries can behave quite differently, and its fundamental organizing principles are still in development. I will give a broad introduction to symmetries on the lattice and how to gauge them. Time permitting, I will discuss subtleties in matching symmetries on the lattice to those in the continuum.

10:30 → 11:00 Coffee break

11:00 → 12:30 Schlank

12:30 → 14:30 Lunch break

Lunch is not provided. Plenty of options for lunch are available nearby.

14:30 → 16:00 Bonetti: Aspects of SymTFT and Continuous Symmetries

In the modern perspective, the generalized global symmetries of a quantum field theory (QFT) are encoded in the spectrum of its (extended) topological operators. Finite symmetries, in particular, are expected to be captured by higher fusion categories. The Symmetry Topological Field Theory (SymTFT) provides a powerful framework for analyzing many facets of these symmetry structures.

While categorical methods and SymTFT techniques are by now well established for finite symmetries, a complete and systematic framework for continuous symmetries is still being developed. In these lectures, I will present some features of SymTFTs for continuous symmetries from a physicist’s perspective. As a complementary approach to better understanding the properties of symmetry operators associated with continuous symmetries, I will also discuss aspects of their realization in holography and string theory.

ven. 19 juin

09:00 → 10:30 Tantivasadakarn: Symmetries and their gauging on the lattice

Much progress of generalized symmetries has been formulated in the continuum. However, on the lattice, symmetries can behave quite differently, and its fundamental organizing principles are still in development. I will give a broad introduction to symmetries on the lattice and how to gauge them. Time permitting, I will discuss subtleties in matching symmetries on the lattice to those in the continuum.

10:30 → 11:00 Coffee break

11:00 → 12:30 Schlank

12:30 → 14:30 Lunch break

Lunch is not provided. Plenty of options for lunch are available nearby.

14:30 → 16:00 Bonetti: Aspects of SymTFT and Continuous Symmetries

In the modern perspective, the generalized global symmetries of a quantum field theory (QFT) are encoded in the spectrum of its (extended) topological operators. Finite symmetries, in particular, are expected to be captured by higher fusion categories. The Symmetry Topological Field Theory (SymTFT) provides a powerful framework for analyzing many facets of these symmetry structures.

While categorical methods and SymTFT techniques are by now well established for finite symmetries, a complete and systematic framework for continuous symmetries is still being developed. In these lectures, I will present some features of SymTFTs for continuous symmetries from a physicist’s perspective. As a complementary approach to better understanding the properties of symmetry operators associated with continuous symmetries, I will also discuss aspects of their realization in holography and string theory.

lun. 22 juin

09:00 → 09:40 McGreevy

09:45 → 10:25 Fidkowski

10:30 → 11:00 Coffee break

11:00 → 11:40 Córdova

11:45 → 12:25 Wen

12:30 → 14:30 Lunch break

Lunch is not provided. Plenty of options for lunch are available nearby.

14:30 → 15:10 Zhang

15:15 → 15:55 Leung

16:00 → 18:00 Poster session + wine and cheese

mar. 23 juin

09:00 → 09:40 Krulewski

09:45 → 10:25 Kapustin

10:30 → 11:00 Coffee break

11:00 → 11:40 Copetti

11:45 → 12:25 Antinucci

12:30 → 14:30 Lunch break

Lunch is not provided. Plenty of options for lunch are available nearby.

14:30 → 15:10 Zhu

15:15 → 15:55 Decoppet

16:00 → 16:40 Debray

17:30 → 19:30 Conference Reception

mer. 24 juin

09:00 → 09:40 Calaque

09:45 → 10:25 Brochier

10:30 → 11:00 Coffee break

11:00 → 11:40 Bottini

11:45 → 12:25 Rayhaun

12:30 → 17:05 Free Afternoon

jeu. 25 juin

09:00 → 09:40 Ji

09:45 → 10:25 Zheng

10:30 → 11:00 Coffee break

11:00 → 11:40 Reutter

11:45 → 12:25 Nivedita

12:30 → 14:30 Lunch break

Lunch is not provided. Plenty of options for lunch are available nearby.

14:30 → 15:10 Pace

15:15 → 15:55 Schäfer Nameki

ven. 26 juin

09:00 → 09:40 Parra-Martinez

09:45 → 10:25 Heckman

10:30 → 11:00 Coffee break

11:00 → 11:40 Steffens

11:45 → 12:25 Müller