Jun Yan

My new webpage is hereLink opens in a new window.

I am a Postdoctoral Scholar position in University of Waterloo working with Professor Luke PostleLink opens in a new window and Professor Michelle DelcourtLink opens in a new window. I was recently a Postdoctoral Research Associate in University of Oxford working with Professor Peter KeevashLink opens in a new window. Previously, I obtained my PhD from University of Warwick under the supervision of Professor Richard MontgomeryLink opens in a new window. My main research interests are Extremal and Enumerative Combinatorics. I can be reached via email at .

Publications

• An intermediate case of exponential multivalued forbidden matrix configurationsLink opens in a new window (arxivLink opens in a new window)

with Wallace PeasleeLink opens in a new window and Attila SaliLink opens in a new window, to appear in The Art of Discrete and Applied Mathematics.

• Multivalued forbidden numbers of two-rowed configurations -- the missing casesLink opens in a new window (arxivLink opens in a new window)

with Wallace PeasleeLink opens in a new window and Attila SaliLink opens in a new window, Discrete Mathematics & Theoretical Computer Science, 28.3 (2026), 17.

• An Erdős--Szekeres type result for words with repeatsLink opens in a new window (arxivLink opens in a new window)

with Kyle CelanoLink opens in a new window, Abigail OllsonLink opens in a new window, and Niraj VelankarLink opens in a new window, Discrete Mathematics & Theoretical Computer Science, 28.1 (2026), 5.

• Descents and inversions in powers of permutationsLink opens in a new window (arxivLink opens in a new window)

with Stijn CambieLink opens in a new window, Enumerative Combinatorics and Applications, 6.2 (2026), S2R13.

• Exponential odd-distance sets under the Manhattan metricLink opens in a new window (arxivLink opens in a new window)

with Alberto Espuny DíazLink opens in a new window, Emma HoganLink opens in a new window, Freddie IllingworthLink opens in a new window, Lukas MichelLink opens in a new window, and Julien PortierLink opens in a new window, The Electronic Journal of Combinatorics, 32.4 (2025), P4.32.

• Lattice paths enumerations weighted by ascent lengthsLink opens in a new window (arxivLink opens in a new window)

Discrete Mathematics, 349.2 (2026), 114783.

• Ramsey numbers of bounded degree trees versus general graphsLink opens in a new window (arxivLink opens in a new window)

with Richard MontgomeryLink opens in a new window and Matías Pavez-SignéLink opens in a new window, Journal of Combinatorial Theory, Series B, 173 (2025), 102-145.

• Results on pattern avoidance in parking functionsLink opens in a new window (arxivLink opens in a new window)

Enumerative Combinatorics and Applications, 5.1 (2025), S2R2.

• Degree sequences of triangular multigraphsLink opens in a new window (arxivLink opens in a new window)

with John TalbotLink opens in a new window, The Electronic Journal of Combinatorics, 31.3 (2024), P3.22.

• Remarks on the distribution of colors in Gallai coloringsLink opens in a new window (arxivLink opens in a new window)

with Joey FefferLink opens in a new window and Yaoying FuLink opens in a new window, Discrete Mathematics, 343.10 (2020), 111996.

Preprints

• Extremal persistence probabilities of exchangeable sign-invariant random variablesLink opens in a new window

with Daniel IľkovičLink opens in a new window, arxiv:2609.05586.

• Exact enumeration of lozenge tilings of a triangular regionLink opens in a new window

arxiv:2607.05233.

• More Shattering NewsLink opens in a new window

with Attila SaliLink opens in a new window, arxiv:2603.18708.

• Ordered Ramsey and Turán numbers of alternating paths and their variantsLink opens in a new window

with Gaurav KucheriyaLink opens in a new window, Allan LoLink opens in a new window, Jan PetrLink opens in a new window, and Amedeo SguegliaLink opens in a new window, arxiv:2603.12358.

• Distribution of independent sets in perfect r-ary treesLink opens in a new window

with Daniel IľkovičLink opens in a new window, arxiv:2601.16953.

• Asymmetric Ramsey numbers of treesLink opens in a new window

arxiv:2511.15673.

• Spanning trees with large maximum degreesLink opens in a new window

arxiv:2510.17736.

• Ramsey numbers of treesLink opens in a new window

with Richard MontgomeryLink opens in a new window and Matías Pavez-SignéLink opens in a new window, arxiv:2509.07934.

• An improved hypergraph Mantel's TheoremLink opens in a new window

with Daniel IľkovičLink opens in a new window, arxiv:2503.14474.

• Multivalued forbidden numbers of two-rowed configurations -- the missing casesLink opens in a new window

with Wallace PeasleeLink opens in a new window and Attila SaliLink opens in a new window, arxiv:2502.04741.

• A note on improved bounds for hypergraph rainbow matching problemsLink opens in a new window

with Candida BowtellLink opens in a new window, Andrea FreschiLink opens in a new window, and Gal KronenbergLink opens in a new window, arxiv:2501.03216.

• Distribution of colours in rainbow H-free colouringsLink opens in a new window

with Zhuo WuLink opens in a new window, arxiv:2309.05606.

Talks

• Exact enumeration of lozenge tilings of a triangular region

Waterloo Algebraic and Enumerative Combinatorics SeminarLink opens in a new window, University of Waterloo, 08/10/2026.

• Ramsey numbers of trees

Waterloo Graphs and Matroids SeminarLink opens in a new window, University of Waterloo, 05/10/2026.

• Asymmetric Ramsey numbers of trees

The 31st British Combinatorial ConferenceLink opens in a new window, Cardiff University, 06/07/2026.

• Ramsey numbers of trees (slidesLink opens in a new window, videoLink opens in a new window)

Shandong University Combinatorics SeminarLink opens in a new window, Shandong University (online), 02/07/2026.

• Ramsey numbers of trees

Oxford Combinatorial Theory SeminarLink opens in a new window, University of Oxford, 10/02/2026.

• An improved hypergraph Mantel's Theorem (slidesLink opens in a new window)

Eurocomb'25Link opens in a new window, Hungarian Academy of Sciences, 27/08/2025.

• Ramsey numbers of trees

The 22nd International Conference on Random Structures & AlgorithmsLink opens in a new window, TU Wien, 07/08/2025.

• An improved hypergraph Mantel's Theorem

The 29th Postgraduate Combinatorial ConferenceLink opens in a new window, University of Glasgow, 30/04/2025.

• Ramsey numbers of trees

LSE PhD Seminar on Combinatorics, Games and OptimisationLink opens in a new window, London School of Economics and Political Science, 24/01/2025.

• Ramsey numbers of trees

UCL Combinatorics SeminarLink opens in a new window, University College London, 25/11/2024.

• Exponential odd-distance sets under the Manhattan metric (slidesLink opens in a new window)

Shandong University Mathematics Rising Stars SeminarLink opens in a new window, Shandong University (online), 12/11/2024.

• A collection of sums over Catalan paths (slidesLink opens in a new window, videoLink opens in a new window)

The 3rd International Conference on Enumerative Combinatorics and ApplicationsLink opens in a new window, University of Haifa (online), 28/08/2024.

• A collection of sums over Catalan paths (slidesLink opens in a new window)

The 30th British Combinatorial ConferenceLink opens in a new window, Queen Mary University of London, 01/07/2024.

• Pattern avoidance in parking functions (slidesLink opens in a new window)

The 28th Postgraduate Combinatorial ConferenceLink opens in a new window, London School of Economics and Political Science, 15/04/2024.

• Ramsey goodness of bounded degree trees versus general graphs (slidesLink opens in a new window)

Birmingham-Warwick Combinatorics MeetingLink opens in a new window, University of Birmingham, 12/12/2023.

• An interesting forbidden matrix problem (slidesLink opens in a new window)

LSE PhD Seminar on Combinatorics, Games and OptimisationLink opens in a new window, London School of Economics and Political Science, 01/12/2023.

• Distribution of colours in rainbow H-free colourings (slidesLink opens in a new window)

Warwick Combinatorics SeminarLink opens in a new window, University of Warwick, 19/05/2023.

• Distribution of colours in Gallai colourings

The 27th Postgraduate Combinatorial ConferenceLink opens in a new window, University of Birmingham, 27/03/2023.

• Counting domino tilings and lozenge tilings (slidesLink opens in a new window)

Warwick Maths Society Talks, University of Warwick, 21/02/2023.

• Ramsey goodness of bounded degree trees versus general graphs

The 20th International Conference on Random Structures and AlgorithmsLink opens in a new window, Institute of European Culture in Gniezno, 01/08/2022.