Workshop on Interactions between Group Theory and Homotopy Theory

July 28 - August 1, 2025, The Fields Institute

Location: Fields Institute, Room 230

Description

Group theory and topology have a long and rich history of interaction. This workshop will bring together experts working on different aspects of this interaction in order to share ideas and boost the development of new methods that can be applied to the topology of configuration spaces, braid groups, mapping class groups and manifolds, and spaces of commuting elements.

Schedule

Monday, July 28th, 2025
09:25 to 09:30	Larry Taylor (Morning Chair)
09:30 to 10:20	Stable Splittings for Spaces of Commuting Elements Alejandro Adem, University of British Columbia
10:20 to 10:40	Coffee Break
10:40 to 11:30	Diffeomorphisms of reducible 3-manifolds Rachael Boyd, University of Glasgow
11:40 to 12:30	Square-section braid groups Jesus Gonzalez (CINVESTAV)
12:30 to 14:30	Lunch
14:25 to 14:30	Shing-Tung Yau (Afternoon Chair)
14:30 to 14:40	Remembering Fred Shing-Tung Yau, Tsinghua University
14:40 to 15:30	Morse complexity Shmuel Weinberger, University of Chicago
15:30 to 16:00	Coffee Break
16:00 to 16:30	Cohomology of toric surfaces Xin Fu, Shanghai Institute for Mathematics and Interdisciplinary Sciences
16:30 to 17:00	Associated Lie algebras of right-angled Coxeter groups and homotopy theory Fedor Vylegzhanin, NRU Higher School of Economics

Tuesday, July 29th, 2025
09:25 to 09:30	Dan Nakano (Morning Chair)
09:30 to 10:20	An Equivariant result and an equivarlant question Peter May (University of Chicago)
10:20 to 10:40	Coffee Break
10:40 to 11:30	(Higher) Scissors congruence and K-theory of covers Anna Marie Bohmann (Vanderbilt University)
11:40 to 12:30	On the work of Fred Cohen. Part I --- the first 25 years. Paul Selick, University of Toronto
12:30 to 14:30	Lunch
14:25 to 14:30	Miguel Xicotencatl (Afternoon Chair)
14:30 to 14:40	Remembering Fred James Stasheff, University of Pennsylvania
14:40 to 15:30	Cohomological homotopy rigidity problem for toric varieties. Jongbaek Song, Pusan National University
15:30 to 16:00	Coffee Break
16:00 to 16:30	On the c_1-spherical bordism theory Georgii Chernykh, NRU Higher School of Economics
16:30 to 17:00	Endomorphisms and Automorphisms of the Framed Little Disk Operad Alice Rolf, University of Toronto
18:30	Buffet dinner in honour of Fred Cohen

Wednesday, July 30th, 2025
09:25 to 09:30	Dave Benson (Morning Chair)
09:30 to 10:20	Geometric groups in homotopy theory Ulrike Tillmann, University of Oxford
10:20 to 10:40	Coffee Break
10:40 to 11:30	Stable Homotopy Groups of Spheres and the Kervaire Invariant Problem Zhouli Xu (UCLA)
11:40 to 12:30	Free Actions on Products of Real Projective Spaces Ergun Yalcin, Bilkent University
12:30 to 14:30	Lunch

Thursday, July 31st, 2025
09:25 to 09:30	Remembering Fred Jie Wu (Morning Chair)
09:30 to 10:20	Topological complexity of random simplicial complexes Michael Farber, Queen Mary University of London
10:40 to 11:30	Uniform Lefschetz fixed point theorem Daisuke Kishimoto, Kyushu University
11:40 to 12:30	Descent and Stratification in Equivariant Homotopy Theory Natalia Castellana, Universitat Autònoma de Barcelona
12:30 to 14:30	Lunch
14:25 to 14:30	Ruth Charney (Afternoon Chair)
14:30 to 14:40	Remembering Fred Peter Landweber
14:40 to 15:30	Graphs, Surfaces and Handlebodies Karen Vogtmann, University of Warwick
15:30 to 16:00	Coffee Break
16:00 to 17:00	Gyration Stability for Projective Planes Sebastian Chenery, University of Bristol, UK
16:30 to 17:00	On Mapping Class Groups of Non-orientable Surfaces Miguel Xicotencatl, Centro de Investigacion y de Estudios Avanzados del IPN

Friday, August 1st, 2025
09:25 to 09:30	Jonathan Pakianathan (Morning Chair)
09:30 to 10:20	Exotic aspherical 4-manifolds Mike Davis, The Ohio State University
10:20 to 10:40	Coffee Break
10:40 to 11:30	Finite group actions on 3-manifolds and Nielsen realization Bena Tshishiku, Brown U
11:40 to 12:30	Scissors automorphism groups and their homology Alexander Kupers, University of Toronto
12:30 to 14:30	Lunch
14:25 to 14:30	Stephen Theriault (Afternoon Chair)
14:40 to 15:30	From Group Actions to Actegories Kathryn Hess, École Polytechnique Fédérale de Lausanne
15:30 to 16:00	Coffee Break
16:00 to 16:50	Finite 2-complexes, Tate cohomology and 4-manifolds Ian Hambleton, McMaster University

Registered Participants

Name	Affiliation
Anshid Aboobacker	Birla Institute of Technology and Science
Alejandro Adem	University of British Columbia
Abderrahim Adrabi
Leonard Afeke	University of Toronto
Marcelo Aguilar	UNIVERSIDAD NACIONAL AUTONOMA DE MEXICO
Tala Alaa Eddine	Beirut Arab University
Mariam Al-Hawaj	Trinity College Dublin
Omar Alvarado	Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV)
Steven Amelotte	Carleton University
Kensuke Arakawa	Kyoto University
Samia Ashraf	GCWUS Pakistan
Alexis Aumonier	Stockholm University
Danyal Azaz	University of Toronto
Hadi Azizi	University of Toronto
Anthony Bahri	Rider University
Andrew Baker	University of Glasgow
Luis Alejandro Barbosa Torres	Pontificia Universidad Javeriana
Samik Basu	Indian Statistical Institute, Kolkata
Sandipan Bhattacherjee	BIRLA INSTITUTE OF TECHNOLOGY MESRA, RANCHI
Andrea Bianchi	Max Planck Institute for Mathematics
Fang Bing	Henan
Terrence Bisson	Canisius College
Anna Marie Bohmann	Vanderbilt University
Michael Borinsky	Perimeter Institute
Rachael Boyd	University of Glasgow
Rachael Boyd	University of Glasgow
Dylan Burke	University of Toronto
Gianmarco Caldini	University of Trento
Luigi Caputi	University of Bologna
Tobin Carlton Van Buizen	Australia National University
Sean Carroll	Northeastern University
Natalia Castellana	Universitat Autònoma de Barcelona
Natalia Castellana Vila
Juan Felipe Celis Rojas	Mathematical Institute - University of Oxford
Ruth Charney	Brandeis University
Himanshu Chaudhary	Albert-Ludwigs-Universitaet Freiburg
Sergio Chaves	Cornell University
Baichuan Chen	University of Utah
Sebastian Chenery	University of Bristol, UK
Herng Yi Cheng	University of Toronto
Georgii Chernykh	NRU Higher School of Economics
Jose Cochegrus	UNIVERSIDAD AUTONOMA DE YUCATÁN
Octav Cornea	Centre de Recherches Mathématiques
Gabriel Corrigan	University of Glasgow
Michael Davis	The Ohio State University
Mike Davis	The Ohio State University
Sanath Devalapurkar	Harvard University
Lore De Weerdt	Katholieke Universiteit Leuven
Soumya Dey	Krea University
Maninder Dhanauta	McGill University
Amartya Dubey	NATIONAL INSTITUTE OF SCIENCE EDUCATION AND RESEARCH (NISER),BHUBANESWAR
Briony Eldridge	University of Southampton
Helen Epelbaum	University of Toronto
Ruslan Erdnigor	University of Toronto
Michael Falk	Northern Arizona University
Michael Farber	Queen Mary University of London
Seher Fişekci	Ankara Science University
Chi-Kwong Fok	Xi'an Jiaotong-Liverpool University
Andreea Fulger	Chalmers University and University of Gothenburg
Xin Fu	Shanghai Institute for Mathematics and Interdisciplinary Sciences
William Gao	University of Toronto
Dominik Gdesz	University of Wroclaw
Surojit Ghosh	Indian Institute of Technology Roorkee
Sacha Goldman	University of Toronto
Tao Gong	Western University
jesus gonzalez	Cinvestav
Vladimir Gorchakov	Western University
Shuchita Goyal	Birla Institute of Technology and Science
Jelena Grbić	University of Southampton
Simon Gritschacher	Ludwig-Maximilians-Universität München
Louis Hainaut	University of Chicago
Ian Hambleton	McMaster University
Megumi Harada	McMaster University
Eric Hayden
Haoyang He	Memorial University
Kathryn Hess	École Polytechnique Fédérale de Lausanne
Joseph Hlavinka	University of California Berkeley
Satyanath Howladar	University of Florida
Hana Huber	CUNY Graduate Center
Jiahao Hu	Yau Mathematical Science Center, Tsinghua University
Elena Isasi Theus	University of Chicago
Sergei Ivanov	Beijing Institute of Mathematical Sciences and Applications
Leo Jiang	University of Toronto
Yoyo Jiang	Johns Hopkins University
Rita Jimenez Rolland	Universidad Nacional Autónoma de México
Aarjav Jogani
Sadok Kallel	American Univeristy of Sharjah
Krishnendu Kar	Louisiana State University
Andrzej Karolak	University of Wrocław
Abdul Khan
Daisuke Kishimoto	Kyushu University
Manuel Krannich	Karlsruhe Institute of Technology
Nursultan Kuanyshov	SDU University
Nicholas Kuhn	University of Virginia
Indrajeet Kumar	Indian Institute of Science Education and Research, Thiruvananthapuram
Alexander Kupers	University of Toronto
Alexander Kupers	Harvard University
Kee Yuen Lam	University of British Columbia
Fengchun Lei	Beijing Institute of Mathematical Sciences and Applications
Ha Le Minh	Vietnam National University, Hanoi
Porfirio Leandro León Álvarez	Instituto de Matematicas UNAM
José Luis León Medina	Centro de Investigación en Matemáticas.(CIMAT)
Ran Levi	University of Aberdeen
Pengcheng Li	Great Bay University
Fangji Liu	University of Pennsylvania
Shane Liu	Toronto Metropolitan University
Yun Liu	Indiana University Bloomington
Zihao Liu	Rice University
Wenwen Li	St. Mary's College of Maryland
Yingxin Li	Beijing Normal University
Cynthia Ma
Mukhammadrizo Madjidov	University of Toronto
Josue Maldonado	Universidad de Guadalajara
sahin mandal	IIT Bombay
Fedor Manin	University of Toronto
Zhouhang Mao	Universiteit van Amsterdam
Vicente Marin-Marquez	University of Toronto
Sofía Martínez Alberga	Purdue University
Clover May	NTNU Norwegian University of Science and Technology
John Peter May	University of Chicago
Ken McCabe	Northeastern University
Amaranta Membrillo Solis	Queen Mary University of London
José Manuel Mendoza
Aleksandar Milivojevic	University of Waterloo
John Miller	Univerisité de Montréal
Qicheng Mi	University of Toronto
EL MOKHTAR MOKKEDEM	Sorbonne University
Maria Morariu	University of Chicago
Marwa Mosallam
Maria M.Parvaiz
Deepak Mundayurvalappil Sadanandan	Western University
Ramana Murugesan	University of Toronto
Suhasiny Naik	UC Irvine
Daniel Nakano	University of Georgia
Taeuk Nam
Joseph Neisendorfer	University of Rochester
Jakob Neumaier	University of Heidelberg
Barry Ngo	University of Ottawa
Urban Ogrinec	Faculty of Mathematics and Physics, University of Ljubljana
Jonathan Pakianathan	University of Rochester
Tamis Panagiotakis	University of Toronto
Lirui Pang	University of Toronto
Taras Panov	NRU Higher School of Economics
Veronica Pasquarella	Shanghai Institute for Mathematics and Interdisciplinary Sciences
Gargi Patil	Louisiana State University
Jan Pearce	Berea College
Andrea Pizzi	University Roma Tor Vergata
Elia Portnoy	Massachusetts Institute of Technology
Bo Rao	University Paris 13
George Raptis	Aristotle University Thessaloniki
Safarul Rasheed	INDIAN INSTITUTE OF SCIENCE EDUCATION AND RESEARCH KOLKATA
Samuel Restoy	University of Oklahoma
Jorge Robinson Arrieta	University of Arkansas
Alice Rolf	University of Toronto
Pratik Roy	Northeastern University
Vasilii Rozhdestvenskii	Steklov Mathematical Institute of Russian Academy of Sciences
Mohamed Amin Sadraoui	Faculty of Sciences of Sfax
Hajime Saeki	University of Toronto
Alejandro Saiz Millán	Universidad de Málaga (UMA)
Sandip Samanta	INDIAN INSTITUTE OF SCIENCE EDUCATION AND RESEARCH KOLKATA
Deepanshi Saraf	Indian Institute of Science Education and Research
Hisham Sati	New York University
Matthew Scalamandre	University of Toronto
Paul Selick	University of Toronto
Pieter Senden
Alisa Senses	University of St Andrews
Kumar Sannidhya Shukla	Western University
Gunjeet Singh	Wayne State University
Kamil Śmietaniak	Adam Mickiewicz university in Poznan
Jongbaek Song	Pusan National University
Tse Leung So	University of Southampton
Mentor Stafa	The Hershey Company
Don Stanley	University of Regina
Lewis Stanton	University of Southampton
James Stasheff	University of Pennsylvania
Yuxuan Sun	University of Toronto
Tan Su	New York University
Niall Taggart	Radboud Universiteit Nijmegen
Jacob Taylor	University of Toronto
Laurence Taylor	University of Notre Dame
Stephen Theriault	University of Southampton
Ulrike Tillmann	University of Oxford
Daniel Tolosa	Arizona State University
Yichen Tong	Westlake University
Victor Torres-Castillo	Pontifical Catholic University of Perú
Bena Tshishiku	Brown U
Bena Tshishiku	Harvard University
Mitsunobu Tsutaya	Kyushu University
Vahid Soleimany	vahid soleimani
Ivan Vasilev	Saint-Petersburg State University
Pravin Kumar Vellaisamy	IISER Mohali
Karen Vogtmann	University of Warwick
Bao Vuong-Huu	Tomsk State University
Fedor Vylegzhanin	NRU Higher School of Economics
Angela Wang	University of Chicago
Elon Wang	University of Toronto
YUYANG WANG	University of Toronto
Alex Waugh	University of Washington
Nicholas Wawrykow	University of Chicago
Peter Webb	University of Minnesota
Jerry Wei	University of California Berkeley
Shmuel Weinberger	University of Chicago
David White	Denison University
Tsz Hin Wong	University of Toronto
Jie Wu	Beijing Institute of Mathematical Sciences and Applications
Miguel Xicotencatl	Centro de Investigacion y de Estudios Avanzados del IPN
Shuhang Xue	University of Minnesota - Twin Cities
Xiaomeng Xu	Beijing Institute of Mathematical Sciences and Applications
Zhouli Xu	University of California, Los Angeles
Ergun Yalcin	Bilkent University
Shiyu Yan	Leiden University
Shing-Tung Yau	Tsinghua University
Sin Hang Jason Yeung	University of Toronto
Ze Yuan	National University of Singapore
Ehsan Zabihi	Amirkabir University of Technology (Tehran Polytechnic)
Indira Zeinikesheva	University of Pittsburgh
Mengmeng Zhang	Beijing Institute of Mathematical Sciences and Applications
Ziwei Zhang	Free University of Berlin
Mingyang Zhou	Tufts University

Organizing Committee

Anthony Bahri - Rider University

Ruth Charney - Brandeis University

Ran Levi - University of Aberdeen

Paul Selick - University of Toronto

Stephen Theriault - University of Southampton

Jie Wu - Beijing Institute of Mathematical Sciences and Applications

Scheduled as part of

Focus Program on Algebraic Topology In memory of Fred Cohen

The Fields Institute for
Research in Mathematical Sciences