Fusion Systems and Localities

Lead Research Organisation: University of Aberdeen
Department Name: Mathematical Sciences

Abstract

The abstract algebraic concept of a group is central in contemporary mathematics, since it allows us to handle objects of a diverse mathematical origin in a uniform way. Groups arise for example from symmetries of other mathematical or geometrical objects. On the other hand, a given group leads again to new algebraic, topological and geometric structures. In particular, to every group one associates a topological space, called the classifying space. This leads to many different ways of studying groups. However, it is a common feature of different approaches that they focus on properties related to a fixed prime p.

Saturated fusion systems provide a new algebraic framework which allows us to discover more and more connections between the different approaches related to a prime. There are however still many open questions remaining. For the prime 2, it is an important long-term goal to classify the simplest building blocks of saturated fusion systems. In this project, we will overcome some major conceptual difficulties arising on the way to such a classification result for fusion systems. This will feed into a simplified proof of the classification of finite simple groups, which is an important theorem classifying the simplest building blocks of finite groups. The new algebraic theory we develop will also allow us to study structure-preserving maps between classifying spaces of groups "at a prime p". We expect that this will open new ways for research in homotopy theory and representation theory.

Planned Impact

Inside mathematics, our research will benefit researchers working in group theory, representation theory and homotopy theory, and it will foster interactions between these different areas. One long-term impact of our project is also a simplified proof of the classification of finite simple groups. This will be of interest to mathematicians from many branches of mathematics.

As our research is in pure mathematics, it is not possible to predict exactly how our results will impact other fields of research or contribute to societal change and economic growth. However, groups and their representations play for example an important role in theoretical physics and in chemistry, and homotopy-theoretical methods are a powerful tool in data analysis.

An immediate and predictable societal impact of our project is the training of the research associate. The research associate will be trained both in analytical and mathematical skills, and in communication skills.

Publications

10 25 50
publication icon
Chermak A (2022) Fusion systems and localities - a dictionary in Advances in Mathematics

publication icon
Henke E (2018) Centralizers of normal subsystems revisited in Journal of Algebra

 
Description We studied generalisation of groups, called localities and proved that many result known from finite group theory carry over.
Exploitation Route The fundamental concepts we developed play most of all a role in a new proof of the classification of finite simple groups. They might also have implications for group representation theory.
Sectors Other

 
Description Normal subsystems of fusion systems and partial normal subgroups of localities 
Organisation Kansas State University
Country United States 
Sector Academic/University 
PI Contribution I worked out the details of the proof that there is a one-to-one correspondence between normal subsystems of fusion systems and partial normal subgroups of localities. I proved on my own that there are one-to-one correspondences between the following: Components of fusion systems and components of localities; the generalized Fitting subsystem of a fusion system and the generalized Fitting subgroup of a locality; products of p-subgroups with normal subsystems of a fusion system and products of p-subgroups with partial normal subgroups of localities.
Collaborator Contribution Prof. Andrew Chermak from Kansas State University gave an outline of the proof that there is a one-to-one correspondence between normal subsystems of fusion systems and partial normal subgroups of localities.
Impact Preprint posted on https://arxiv.org/abs/1706.05343. Significantly expanded version of this preprint with important new results written as part of the EPSRC funded project "Fusion systems and Localities" yet unpublished.
Start Year 2017
 
Description Maths competition 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Talk to participants of a maths competition organized by our department for pupils from Schools in Aberdeenshire. The purpose of the talk was to spark pupil's interest in mathematics (with the hope that at least some of them might choose to study mathematics later on). While the long-term impact is still unclear, the talk definitely sparked interested questions and discussions.
Year(s) Of Engagement Activity 2018
 
Description PGTC St Andrews 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Talk on a conference for PhD students in group theory, most of them from the UK, but some also from abroad. Talk educated PhD students about the classification of finite simple groups, one of the major mathematical achievements of 20th century mathematics, and explained how it is connected to my research. I estimate that for about half of the attendees, this is useful knowledge for their own research, for the other half it contributes to their general mathematical knowledge.
Year(s) Of Engagement Activity 2018
URL http://www-groups.mcs.st-and.ac.uk/~pgtc2018/#home