Currently I am a Junior Research Fellow at Trinity Hall, Cambridge. Before that, I did my PhD in Combinatorics and Optimization with Jim Geelen at the University of Waterloo between 2018 and 2022. I am interested in graph and matroid theory and their interactions with geometry. My email address is jgd37 at cam dot ac dot uk.
31. Counterexample to the conjectured coarse grid theorem, https://arxiv.org/abs/2508.15342, submitted (with Sandra Albrechtsen)
30. Binary matroids and degree-boundedness for pivot-minors, https://arxiv.org/abs/2507.23182, submitted (with Rutger Campbell, and Robert Hickingbotham)
29. Odd coloring graphs with linear neighborhood complexity, https://arxiv.org/abs/2506.08926, submitted (with Meike Hatzel, Kolja Knauer, Rose McCarty, and Torsten Ueckerdt)
28. Girth in GF(q)-representable matroids, https://arxiv.org/abs/2504.21797, Bulletin of the London Mathematical Society, to appear (with Meike Hatzel, Kolja Knauer, Rose McCarty, and Torsten Ueckerdt)
27. Preparing graph states forbidding a vertex-minor, https://arxiv.org/abs/2504.00291, submitted (with Andrew Jena)
26. Strongly sublinear separators and bounded asymptotic dimension for sphere intersection graphs, https://arxiv.org/abs/2504.00932, submitted (with Agelos Georgakopoulos, Meike Hatzel, and Rose McCarty)
25. Quasi-isometries between graphs with variable edge lengths, https://arxiv.org/abs/2503.07448, submitted (with Meike Hatzel, and Robert Hickingbotham)
24. Colouring t-perfect graphs, https://arxiv.org/abs/2412.17735, submitted (with Maria Chudnovsky, Linda Cook, Sang-il Oum, and Jane Tan)
23. On high genus extensions of Negami's conjecture, https://arxiv.org/abs/2412.04420, submitted (with Marcin Briański, and Jane Tan)
22. Treewidth, Hadwiger number, and induced minors, https://arxiv.org/abs/2410.19295, submitted (with Rutger Campbell, Marc Distel, Bryce Frederickson, Pascal Gollin, Kevin Hendrey, Robert Hickingbotham, Sebastian Wiederrecht, David Wood, and Liana Yepremyan)
21. Counterexample to Babai's lonely colour conjecture, https://arxiv.org/abs/2410.05199, submitted (with Meike Hatzel, and Liana Yepremyan)
20. Polynomial Gyárfás-Sumner conjecture for graphs of bounded boxicity, https://arxiv.org/abs/2407.16882, submitted (with Yelena Yuditsky)
19. Fat minors cannot be thinned (by quasi-isometries), https://arxiv.org/abs/2405.09383, submitted (with Robert Hickingbotham, Freddie Illingworth, and Rose McCarty)
18. Geometric graphs with exponential chromatic number and arbitrary girth, https://arxiv.org/abs/2312.06898, The American Mathematical Monthly, to appear (with Matija Bucić)
17. Prime and polynomial distances in colourings of the plane, https://arxiv.org/abs/2308.02483, Israel Journal of Mathematics, to appear (with Rose McCarty, and Michał Pilipczuk)
16. A solution to Ringel's circle problem, https://arxiv.org/abs/2112.05042, Journal of the European Mathematical Society, to appear (with Chaya Keller, Linda Kleist, Shakhar Smorodinsky, and Bartosz Walczak)
15. Reuniting χ-boundedness with polynomial χ-boundedness, https://arxiv.org/abs/2310.11167, Journal of Combinatorial Theory, Series B, 176:30--73, 2026 (with Maria Chudnovsky, Linda Cook, and Sang-il Oum)
14. Pivot-minors and the Erdős-Hajnal conjecture, https://arxiv.org/abs/2305.09133, Journal of Combinatorial Theory, Series B, 173:257--278, 2025
13. Chromatic number of spacetime, https://arxiv.org/abs/2308.16885, Acta Arithmetica, 218(1):65--76, 2025
12. On polynomial degree-boundedness, https://arxiv.org/abs/2311.03341, Advances in Combinatorics, 2024:5, 16pp (with Romain Bourneuf, Matija Bucić, and Linda Cook)
11. Odd distances in colourings of the plane, https://arxiv.org/abs/2209.15598, Geometric and Functional Analysis, 34(1):19--31, 2024
10. Separating polynomial χ-boundedness from χ-boundedness, https://arxiv.org/abs/2201.08814, Combinatorica, 44(1):1--8, 2024 (with Marcin Briański, and Bartosz Walczak)
9. Grounded L-graphs are polynomially χ-bounded, https://arxiv.org/abs/2108.05611, Discrete & Computational Geometry, 70(4):1523–1550, 2023 (with Tomasz Krawczyk, Rose McCarty, and Bartosz Walczak)
8. Triangle-free graphs with large chromatic number and no induced wheel, https://arxiv.org/abs/2104.05907, Journal of Graph Theory, 103(1):112--118, 2023
7. Colouring polygon visibility graphs and their generalizations, https://arxiv.org/abs/2103.07803, Journal of Combinatorial Theory, Series B, 161:268--300, 2023 (with Tomasz Krawczyk, Rose McCarty, and Bartosz Walczak)
6. Improved bounds for colouring circle graphs, https://arxiv.org/abs/2107.03585, Proceedings of the American Mathematical Society, 150(12):5121--5135, 2022
5. Vertex-minor-closed classes are χ-bounded, https://arxiv.org/abs/2008.05069, Combinatorica, 42(Suppl 1):1049--1079, 2022
4. Box and segment intersection graphs with large girth and chromatic number, https://arxiv.org/abs/2011.14174, Advances in Combinatorics, 2021:7, 9pp
3. Edge-maximal graphs on orientable and some nonorientable surfaces, https://arxiv.org/abs/1911.02666, Journal of Graph Theory, 98(3):405--425, 2021 (with Florian Pfender)
2. Circle graphs are quadratically χ-bounded, https://arxiv.org/abs/1905.11578, Bulletin of the London Mathematical Society, 53(3):673--679, 2021 (with Rose McCarty)
1. Locally Hamiltonian graphs and minimal size of maximal graphs on a surface, https://arxiv.org/abs/2001.04836, The Electronic Journal of Combinatorics 27(2), (2020), #2.25 (with Carsten Thomassen)