a picture of me, smiling

Will J. Turner

Research

I am a research assistant and doctoral candidate at TU Bergakademie Freiberg, Sachsen. A link to my group's webpage can be found here. I am in the structural combinatorics team headed by Prof. Johannes Carmesin.

Current research interests

Topological combinatorics. Planar graph theory and higher-dimensional analogues.
Connectivity theory and graph decomposition. Finding and using canonical ways to break down combinatorial objects.
Matroids. Matroid representability.
I often combine the above with complexity theory and sometimes category theory.

Ongoing collaborations

With Prof. Johannes Carmesin developing a graph minor theory for temporal sequences.
With Dr Benjamin Merlin Bumpus on an algebraic dual to tree-width.
With Dr Matthew Kroeker, trying to simultaneously represent temporal matroids.

Papers

Hardness of planarity for weak temporal sequences of 2-connected graphs Johannes Carmesin, Will J. Turner
preprint December 2025 arxiv
A graph minors approach to temporal sequences Johannes Carmesin, Will J. Turner
preprint April 2025 to appear: STOC 2026 arxiv
Pushing tree decompositions along graph homomorphisms Benjamin Merlin Bumpus, James Fairbanks, Will J. Turner
preprint August 2024 arxiv
Towards a Stallings-type theorem for finite groups Johannes Carmesin, Jan Kurkofka, George Kontogeorgiou, Will J. Turner
preprint March 2024 arxiv

Upcoming

ProofBench: a Lean-based proof verification and generation benchmark for AI
Leaning In! Berlin
12th March 2026

Resarch visit

Universidad São Paulo
24th March - 27th April 2026

Recent events

ProofBench Initiative
TU Freiberg
September 2025

Selected talks

Temporal sequences
Research Seminar DMA - TU Freiberg
12th Nov 2025
Temporal sequences
Bertinoro Workshop on Algorithms and Graphs
29th Oct 2025
Temporal sequences
SEG workshop Chemnitz
30th June 2025
Invited Minisymposium: Matroid Theory
CanaDAM - U Ottowa
22nd May 2025
A graph minors approach to temporal sequences
Forschungsseminare - U Hamburg
29th Apr 2025
Coloured matroid reconstruction: part 2
Research Seminar DMA - TU Freiberg
06th Nov 2024
Coloured matroid reconstruction: part 1
Research Seminar DMA - TU Freiberg
30th Oct 2024
Towards a Stallings-type theorem for finite groups: part 2
Research Seminar DMA - TU Freiberg
03rd Jul 2024
Towards a Stallings-type theorem for finite groups: part 1
Research Seminar DMA - TU Freiberg
22nd May 2024
A forbidden substructure characterisation of temporal planarity
Combinatorics Seminar - University of Warwick
23nd Feb 2024
Forbidden Spiders: a forbidden substructure characterisation of temporal planarity
Combinatorics Seminar - University of Birmingham
12th Oct 2023
Local separators of Cayley graphs
QTMC Conference - Queen Mary University London
07th Jul 2023
What on earth is a matroid: A journey through topological graph theory to Rota's conjecture
Pure Détour - University of Birmingham
21st Apr 2023
Local separators of Cayley graphs
Postgraduate Combinatorics Conference - University of Birmingham
29th Mar 2023

Demonstrating

Lineare Algebra Übungsklasse
TU Freiberg
Winter 2025
Komplexitätstheorie Übungsklasse
TU Freiberg
Summer 2025
Algorithmic Graph Theory 2 exercise classes
TU Freiberg
Summer 2025
Algorithmic Geometry exercise classes
TU Freiberg
Winter 2024
Algorithmics exercise classes
TU Freiberg
Summer 2024
a painting of a forest pool