Pieter Naaijkens' homepage

Naomi featured in news article; new roles

Sun, 26 Jul 2026 12:00:00 +0200

My PhD student Naomi Wray has been featured in a news article on deaf accessibility on the School’s website. Naomi is profoundly deaf and wears a cochlear implant. At the recent British Mathematical Colloquium held in Cardiff, she gave an invited talk on how mathematics events can be made more accessible to people with hearing problems. A feature article on this topic written by her will appear in an upcoming issue of the London Mathematical Society’s Newsletter. Well done Naomi for creating this positive impact!

In other news, Cardiff University’s School of Mathematics will be merging with the School of Computer Sciences and Informatics to form the new School of Computational and Mathematical Sciences. I have been appointed to two roles in the new school, in part continuing roles I currently hold. The first is that of Course Coordinator (Year 2 Mathematics). In this role, I provide oversight over our Year 2 curriculum in mathematics, chair exam boards, and provide advice to students and personal tutors. The second role is that of Disability Coordinator (Undergraduate, across mathematics and computer science). In this role I coordinate support for students with a disability and make sure reasonable adjustments are made to support students, and advise staff on practical measures they can take to make our teaching more accessible.

Please get in touch with me directly if you have any queries falling within the remit of these two roles.

NeoVim plugin to retrieve BibTeX data

Sat, 27 Dec 2025 11:00:00 +0100

As a fun little project for the Christmas break, I made a plugin, getbib.nvim, for the NeoVim editor. This plugin uses pybibget to retrieve BibTeX date and insert it directly in the editor. The data can be searched by arXiv ID, DOI, or MathSciNet reference number (the latter with a subscription), making it easier to add new references. Optionally, the generated BibTeX can be filtered through a formatter such as bibtex-tidy to ensure consistent formatting of entries. The plugin with instructions can be found on GitHub.

British Mathematical Colloquium 2026 in Cardiff

Tue, 18 Nov 2025 16:00:00 +0100

The British Mathematical Colloquium (BMC) is the principal cross-disciplinary pure mathematical conference in the UK, taking place annually since 1949. In 2026, it will be held in Cardiff, from 30 March until 2 April. Together with Ana Ros Camacho and Simon Wood, I am organising the Mathematical Physics section. We are accepting proposals for contributed talks. On the registration website, linked below, you can indicate if you’re interested in giving a talk.

Registration for the conference is through the conference website, where more information can be found. Please note that there is an early bird discount of the registration fees until 31 December!

Welcome to Valerio!

Sat, 01 Nov 2025 10:00:00 +0100

Today, Valerio Bianchi started as a postdoctoral research, supported by a 5-month fellowship within EPSRC’s “Postdoctoral Pathways for Growth” scheme. Valerio recently submitted his PhD thesis, supervised by Ulrich Pennig. This scheme will help Valerio to further develop his own research programme and take the next steps in his career. He works on the interplay between homotopy theory and operator algebras, and is currently working on classifying C^* -algebras and group actions on C^*-algebras by means of topological invariants.

Upcoming talks and events

Wed, 16 Apr 2025 17:00:00 +0200

I will be visiting and organising a number of events in the coming months. At some of them I will be giving a number of invited lectures. Details are as follows:

On 14 May, I will give a 2 hour introduction to tensor categories in the LMS South West&South Wales Regional Meeting and Workshop.
On 5 and 6 June we are organising the 10th workshop of the “AQFT in the UK” research group funded by the London Mathematical Society. The event will be held in Cardiff. For more information, see the web page.
From 30 June until 11 July, a twinned workshop on Quantum Field Theory and Topological Phases via Homotopy Theory and Operator Algebras will be held jointly in Harvard and at the Max Planck Institute for Mathematics in Bonn. The first week will consist of a series of lectures by Hopkins, Kitaev, Nachtergaele and myself aimed at graduate students. The second will is a conference. I will be attending the Bonn location.
From 27 July to 1 August I am attending the Oberwolfach workshop on Subfactors and Applications, organised by Dietmar Bisch, Terry Gannon, Yasu Kawahigashi and Yoshiko Ogata.

Congratulations to Mahdie!

Fri, 21 Feb 2025 10:00:00 +0100

Congratulations to my PhD student Mahdie Hamdan! He successfully passed his viva on 25 November 2025. The external examiner was Prof. Daniel Ueltschi (Warwick), and internal examiner Dr Ana Ros Camacho. The viva was chaired by Dr Jonathan Thompson. Many thanks to all of them!

Mahdie has now implemented the minor revisions requested by the examiners. His thesis is titled Infinite volume ground states in the non-Abelian quantum double model, and can be found by clicking the link.

Funding success

Sun, 15 Dec 2024 10:00:00 +0100

My two applications to the Taith scheme funded by the Welsh government have been successful. With a Taith incoming research mobility grant, I will be able to support a visit of Alan Getz from Vancouver. With another Taith grant I will be able to attend a research workshop on Subfactors and Applications in Oberwolfach. My Phd student Naomi Wray was also successful in applying, and will be visiting the group of Sven Bachmann in February 2025. Congratulations!

I also have made a successful application to the University Research Leave scheme. This will allow me to fully focus on my research in Spring 2026. It also comes with travel funding to visit and invite collaborators.

Funded PhD position available

Sun, 11 Dec 2022 10:00:00 +0100

I have a fully funded (by EPSRC) PhD studentship available with project title The mathematics of exotic phases: fractons, with a start in July or October 2023. This studentship is part of the Quantum Materials Interdisciplinary Doctoral Training Hub. This is a project in mathematical physics: you will be based in the School of Mathematics at Cardiff University, but there will be plenty of opportunity to interact with physicists. In particular, the second supervisor is Felix Flicker. Interested students with a background in mathematics, theoretical physics, or a closely related

The goal of the project is to study exotic phases of matter, in particular those which have fractonic excitations from an operator-algebraic point of view. This builds on previous successes for the study of topologically ordered phases, and anyons in particular. More details about the project and information regarding the position can be found on the FindAPhD website. For more information feel free to contact me.

How to apply

Please read the information on the FindAPhD website for all information around the project and application procedure. Applicants should apply through the Cardiff University online application portal on the following website:

https://www.cardiff.ac.uk/study/postgraduate/research/programmes/programme/mathematics

Choose “Doctor of Philosophy in Mathematics” with an entry point of June 2023 or October 2023 in the box on the right hand side. In the research proposal section of your application, please specify the project title supervisors of this project. In the funding section, please specify that you are applying for advertised funding from the EPSRC-funded QuMat IDTH. Please include the following in your application:

your academic CV
a personal statement
two completed references
current academic transcripts

The deadline for applications is 27 January 2023. We hope to be able to interview shortlisted candidates not long after that.

Virtual LQP workshop

Thu, 16 Apr 2020 11:00:00 +0200

We are organising an online workshop in the Local Quantum Physics series of workshops from 17 to 19 June. This is already the 45th instalment, and the first virtual one. The idea was born after the planned LQP workshop in Paderborn had to be postponed due to the current lockdown. This online workshop will in particular give junior researchers the opportunity to share their results. As an added benefit, this will allow members of the LQP community all over the world to participate.

We welcome contributions in the areas of quantum field theory, quantum statistical mechanics, quantum information, non-commutative geometry, quantum gravity and cosmology, and related topics of mathematical physics and mathematics. More information and a registration form can be found on the homepage.

Funded PhD position available

Tue, 11 Feb 2020 10:00:00 +0100

We have an EPSRC funded PhD studentship in mathematics available, with project title Operator Algebraic Methods in Topological Phases and Quantum Information. The project will be supervised by myself, with Gandalf Lechner acting as a co-supervisor. The deadline for applications is 16 March 2020.

The goal of the project is to use rigorous operator algebraic methods to describe quantum systems with infinitely many degrees of freedom. The applications we will consider in particular are towards topologically ordered quantum spin systems, and quantum information theory for ssytems with infinitely many degrees of freedom. Within the project there are various mathematical directions that can be taken, so as a PhD student you will be able to choose those that you find most interesting. More details about the project and information regarding the vacancy can be found on the FindAPhD website. For more information feel free to contact me.

How to apply

Applicants should apply through the Cardiff University online application portal on the follwing website:

https://www.cardiff.ac.uk/study/postgraduate/research/programmes/programme/mathematics

Choose “Doctor of Philosophy in Mathematics” with an entry point of October 2020 in the box on the right hand side. In the research proposal section of your application, please specify the project title and supervisors of this project. In the funding section, please select “I will be applying for a scholarship / grant” and specify that you are applying for advertised funding from EPRSC DTP. Shortlisted candidates will be interviewed in April.