All combinatorics seminar talks are Tuesday 2-3pm in APM 7321 (during the academic quarter), unless otherwise announced.
If you are interested in giving a talk (or want to be added to our mailing list), please email one of the organizers: Brendon Rhoades or Lutz Warnke.
For previous talks, please see the seminar archive: 2023, 2022, 2021, 2020, 2019, 2018, 2017.
Tuesday, May 27, 2025, 2:00pm, APM 7321
He Guo (Umeå University)
TBA
Tuesday, May 13, 2025, 2:00pm, APM 7321
Lutz Warnke (UCSD)
Optimal Hardness of Online Algorithms for Large Independent Sets Abstract,
Preprint
Tuesday, May 6, 2025, 2:00pm, APM 7321
Jiaxi Nie (Georgia Institute of Technology)
Generalized Erdos-Rogers problems for hypergraphs Abstract
Tuesday, April 22, 2025, 2:00pm, APM 7321
Stephan Pfannerer (University of Waterloo)
Rotation-invariant web bases from hourglass plabic graphs Abstract
Tuesday, April 8, 2025, 2:00pm, APM 7321
Mikhail Isaev (UNSW Sydney)
Counting Eulerian Orientation: Abstract, Preprint I, Preprint II
Tuesday, April 1, 2025, 2:00pm, APM 7321
Organizational meeting (and social gathering)
Tuesday, March 18, 2025, 2:00pm, APM 5829 (Non-standard room)
Tianyi Yu (UQAM)
An insertion algorithm for Schubert Cauchy identity via Pieri formula:
Abstract
Tuesday, March 18, 2025, 1:00pm, APM 5829 (Non-standard time and room)
Jack Chou (University of Florida)
Grothendieck Polynomials of Inverse Fireworks Permutations: Abstract
Tuesday, March 4, 2025, 2:00pm, APM 7321
Ada Stelzer (UIUC)
Crystals, standard monomials, and filtered RSK: Abstract
Monday, February 24, 2025, 2:00pm, APM 6402 (Non-standard date and time and room)
Carly Klivans (Brown University)
The Arboricity Polynomial: Abstract
Tuesday, February 18, 2025, 2:00pm, APM 7321
John Peca-Medlin (UC San Diego)
Heights of butterfly trees:
Abstract
Tuesday, February 11, 2025, 2:00pm, APM 7321
Sara Billey (University of Washington)
Enumerating Quilts of Alternating Sign Matrices and Generalized Rank Functions: Abstract
Tuesday, February 4, 2025, 2:00pm, APM 7321
Sutanay Bhattacharya (UC San Diego)
Hilbert Series of the type B Superspace Coinvariant Ring: Abstract
Tuesday, January 14, 2025, 2:00pm, APM 7321
Sam Spiro (Rutgers University)
The Random Turan Problem: Abstract
Tuesday, January 7, 2025, 2:00pm, APM 7321
Akihiro Miyagawa (UC San Diego)
Q-deformation of independent Gaussian random variables in non-commutative probability: Abstract
Tuesday, December 3, 2024, 2:00pm, APM 7321
Andrew Suk (UC San Diego)
Intersection patterns of pseudo-segments: Abstract
Tuesday, November 26, 2024, 2:00pm, APM 7321
Yi Zhao (Georgia State University)
Extremal results in multipartite graphs: Abstract
Tuesday, November 19, 2024, 2:00pm, APM 7321
Shachar Lovett (UC San Diego)
Spread regularity and applications: Abstract
Tuesday, November 12, 2024, 2:00pm, APM 7321
Jiayi Wen (University of Southern California)
Demazure crystals for flagged key polynomials Abstract,
Preprint
Tuesday, November 5, 2024, 2:00pm, APM 7321
Miquel Ortega (UPC Barcelona)
A canonical van der Waerden theorem in random sets: Abstract, Preprint
Tuesday, November 5, 2024, 1:00pm, APM 7321
Jasper Liu (UC San Diego)
Matrix loci and orbit harmonics: Abstract
Joint Combinatorics-Probability seminar
Thursday, October 31, 2024, 11:00am, APM 6402 (Zoom-Talk: Meeting ID: 980 5804 6945, Password: 271781)
Marton Szőke (Budapest University of Technology)
Local Limit of the Random Degree Constrained Process: Abstract, Preprint
Tuesday, October 29, 2024, 2:00pm, APM 7321
Nicholas Sieger (Iowa State University)
Ricci Curvatures in Random Clustering Graphs: Abstract
Tuesday, October 22, 2024, 2:00pm, APM 7321
Ji Zeng (Alfréd Rényi Institute of Mathematics)
Unbalanced Zarankiewicz problem for bipartite subdivisions: Abstract
Tuesday, October 15, 2024, 2:00pm, APM 7321 (Zoom-Talk: Meeting ID: 941 1988 0012, Password: 634921)
Zhifei Yan (IMPA)
The chromatic number of very dense random graphs: Abstract, Preprint
Tuesday, October 8, 2024, 2:00pm, APM 7321
Youngho Yoo (Texas A&M University)
Erdos-Posa property in group-labelled graphs: Abstract, Preprint
Tuesday, October 1, 2024, 2:00pm, APM 7321
Organizational meeting (and social gathering)
| 2023-2024 | |||
| DATE | SPEAKER | TITLE | ABSTRACT |
| » June 11th (in APM 6402) | Tolson Bell (Carnegie Mellon University) | Random Hypergraphs and O(1) Insertion for Cuckoo Hashing | Abstract |
| » June 4th | Lutz Warnke (UCSD) | Extreme local statistics in random graphs: maximum tree extension counts | Abstract |
| » May 28th Canceled | Harold Polo (UC Irvine) | Cancelled | TBA |
| » May 21st | Mike Molloy (University of Toronto) | An improved bound for the List Colouring Conjecture | Abstract |
| » May 14th | Jane Gao (University of Waterloo) | Evolution of random representable matroids | Abstract |
| » April 23rd | Colleen Robichaux (UCLA) | Exploring Kohnert's rule for Grothendieck polynomials | Abstract |
| » April 16th Canceled | Miquel Ortega (UPC Barcelona) | Cancelled | TBA |
| » April 9th | Ewan Cassidy (Durham University) | Schur-Weyl duality for symmetric groups | Abstract |
| » March 19th (in APM 7218) | Sylvester Zhang (U Minnesota) | Schubert calculus and the Boson-Fermion correspondence | Abstract |
| » March 12th | Maciej Dolega (Polish Academy of Sciences) | Weighted b-Hurwitz numbers from W-algebras | Abstract |
| » March 5th | Tom Bohman (Carnegie Mellon University) | Notes on 2-point concentration in the random graph | Abstract |
| » February 27th | Vic Reiner (U Minnesota) | Descents, peaks, and configuration spaces | Abstract |
| » February 20th | Jiyang Gao (Harvard) | Quantum Bruhat graphs and tilted Richardson varieties | Abstract |
| » February 13th | Marcelo Sales (UC Irvine) | On Pisier type problems | Abstract |
| » February 6th | Mike Molloy (University of Toronto) | k-regular subgraphs near the k-core threshold of a random graph | Abstract |
| » January 30th | Zach Hamaker (University of Florida) | Duality for polynomials | Abstract |
| » January 23th | Martin Balko (Charles University Prague) | Ordered Ramsey numbers: Some recent progress | Abstract |
| » January 16th | Jonathan Novak (UCSD) | From Graph Theory to Yang-Mills Theory via Math 202B | Abstract |
| » January 9th | Sam Spiro (Rutgers University) | Sidorenko Hypergraphs and Random Turan Numbers | Abstract |
| » December 5th | Freddie Manners (UCSD) | On a conjecture of Marton | Abstract |
| » November 28th (zoom) | He Guo (Technion) | Non-uniform degrees and rainbow versions of the Caccetta-Häggkvist conjecture | Abstract |
| » November 14th | Daniel Soskin (Lehigh University) | Multiplicative and additive determinantal inequalities for totally nonnegative matrices | Abstract |
| » November 7th | Tianyi Yu (UCSD) | Analogue of Fomin-Stanley algebra on bumpless pipe dreams | Abstract |
| » October 31st | Jacques Verstraete (UCSD) | The asymptotics of r(4,t) | Abstract |
| » October 16th at 2pm (Monday) | Esme Bajo (UC Berkeley) | Weighted Ehrhart Theories | Abstract |
| » October 10th | Yifeng Huang (University of British Columbia) | In the absence of partitions | Abstract |
| » October 3rd | Shira Zerbib (Iowa State University) | New bounds on piercing numbers and line-piercing numbers in families of convex sets in the plane | Abstract |
| 2022-2023 | |||
| DATE | SPEAKER | TITLE | ABSTRACT |
| » November 7th (on MONDAY at 4pm in 5402 APM) | Raymond Chou | A descent basis for the Garsia-Procesi module | Abstract |
| » November 15th | Gidon Orelowitz | The Kostka semigroup and its Hilbert basis | Abstract |
| » November 22nd | Ruixiang Zhang | A nonabelian Brunn-Minkowski inequality | Abstract |
| » January 10th | Yibo Gao | Symmetric structures in the strong Bruhat order | Abstract |
| » January 17th | Sara Billey | Combinatorial characterizations of smooth positroid varieties via pattern avoidance, spirographs, and Johnson graphs | Abstract |
| » January 24th | Tianyi Yu | Top degree components of Grothendieck and Lascoux polynomials | Abstract |
| » January 31st | Sam Mattheus | Non-opposite sets of flags in geometries over finite fields | Abstract |
| » February 7th | Sarah Brauner | Configuration spaces and combinatorial algebras | Abstract |
| » February 14th | Jianping Pan | RSK tableaux of boolean and fully commutative permutations | Abstract |
| » March 7th | Boris Bukh | Enumeration of interval graphs and d-representable complexes | Abstract |
| » March 14th | Sami Assaf | An insertion algorithm on Schubert polynomials | Abstract |
| » April 11th | Satyan Devadoss | Combinatorics of surface deformations | Abstract |
| » May 2nd | Geertrui van de Voorde | Point sets with few intersection numbers in projective spaces | Abstract |
| » May 9th | Sam Spiro | Clique and Berge Supersaturation for K_{2,t} | Abstract |
| » May 23rd | Brendon Rhoades | The superspace coinvariant ring | TBA |
| » May 30th | Lutz Warnke (UCSD) | Isomorphisms between dense random graphs | Abstract |
| » June 6th | Jesse Kim | Web bases and noncrossing set partitions | TBA |
| 2021-2022 | |||
| DATE | SPEAKER | TITLE | ABSTRACT |
| » September 28th | Ruth Luo | Title: A Dirac Theorem for hamiltonian hypergraphs | Abstract |
| » October 5th | Sam Spiro | Title: Maximal Independent Sets in Clique-free Graphs | Abstract |
| » October 12th | Tianyi Yu | Title: Grothendieck-to-Lascoux Expansions | Abstract |
| » November 2nd | Andrew Zucker | Title: Big Ramsey degrees in binary free amalgamation classes | Abstract |
| » November 9th | Ferdinand Ihringer | Title: Low degree sets in finite geometry | Abstract |
| » November 16th | Josh Swanson | Title: DUSTPAN distributions as limit laws for Mahonian statistics on forests | Abstract |
| » November 23rd | Anton Bernshteyn | Title: Weak degeneracy of graphs | Abstract |
| » November 30th | Jonathan Tidor | Title: Joints of varieties | Abstract |
| » December 7th | Jaeseong Oh | Title: A combinatorial model for the transition matrix between the Specht and web bases | Abstract |
| » January 11th | Christophe Hohlweg | Title: TBA | Abstract |
| » May 31st | Lutz Warnke (UCSD) | The degree-restricted random process is far from uniform | Abstract |
| 2019-2020 | |||
| DATE | SPEAKER | TITLE | ABSTRACT |
| » April 7 Canceled | Anton Bernshteyn | Title: TBA | Abstract |
| » March 17 | Kevin Milans | Title: TBA | Abstract |
| » March 10 | Erin Meger | Title: The Iterated Local Model for Social Networks | Abstract |
| » March 3 | Krystal Guo | Title: Inverses of Trees | Abstract |
| » February 27 at 2pm in APM 7218 | Chun-Hung Liu | Title: Clustered coloring for Hadwiger-type conjectures | Abstract |
| » February 18 | Christophe Hohlweg | Title: Garside shadow and Shi arrangements in Coxeter groups | Abstract |
| » February 11 | Chris Cox | Title: Periodic words, common subsequences and frogs | Abstract |
| » February 4 | Rekha Biswal | Title: Macdonald polynomials and level two Demazure modules for affine sl(n+1) | Abstract |
| » January 28 | Tianyuan Xu | Title: On elements of a-value 2 in Coxeter groups | Abstract |
| » January 14 | Swee Hong Chan | Title: Performing random walks without any randomness | Abstract |
| » January 7 | Gweneth Anne McKinley | Title: Super-logarithmic cliques in dense inhomogeneous random graphs | Abstract |
| » December 12 at 3pm in APM 6402 | Radoslav Fulek | Title: Atomic embeddability, clustered planarity, and thickenability | Abstract |
| » December 4 at 2pm in APM 7321 | Taylor Brysiewicz | Title: The degrees of Stiefel manifolds | Abstract |
| » December 3 | Lina Li | Title: An overview of Erdos-Rothschild problems and their rainbow variants | Abstract |
| » November 26 | Misha Lavrov | Title: Ordered size Ramsey number of paths | Abstract |
| » November 21 at 3:00pm in APM 6402 | Cosmin Pohoata | Title: Sets without 4APs but with many 3APs | Abstract |
| » November 12 | Xujun Liu | Title: Monochromatic connected matchings, paths and cycles in 2-edge-colored multipartite graphs | Abstract |
| » November 5 | Satyan Devadoss | Title: Unfolding geometry at Burning Man | Abstract |
| » October 29 | Zhiyu Wang | Title: Finding Berge hypergraphs by looking at the shadow | Abstract |
| » October 15 | Natan Rubin | Title: Planar point sets determine many pairwise crossing segments | Abstract |
| 2018-2019 | |||
| DATE | SPEAKER | TITLE | ABSTRACT |
| » May 28th | Robert Ladoune | Title: Representation stability for 0-Hecke modules | Abstract |
| » May 21st at 12:00pm in APM 6402 | Ruth Luo | Title: 2-connected hypergraphs with no long cycles | Abstract |
| » May 16th at 2:00pm | Hao Huang | Title: A spectral proof of Kleitman's diametric theorem | Abstract |
| » May 14th | Sean Griffin | Title: Labeled binary trees, subarrangements of the Catalan arrangements, and Schur-positivity | Abstract |
| » May 7th | Eric Ramos | Title: Categories of graphs and contractions | Abstract |
| » May 1st at 3:00pm | Deborah Oliveros | Title: Tverberg-type theorems and intersection patterns | Abstract |
| » April 23rd | Sheila Sundaram | Title: The Kronecker coefficients from Jacobi's alternant formula for the Schur function | Abstract |
| » March 21th at 4pm, APM 2402 | Janos Pach | Title: The blessing of low dimensionality (Department Colloquium) | Abstract |
| » March 19th at 4pm, APM 6402 | Jacob Fox | Title: Regularity methods: applications and limitations (Department Colloquium) | Abstract |
| » March 19th | Sam Spiro | Title: Saturation games for odd cycles | Abstract |
| » March 12th | Jason O'Neill | Title: Bollobas set k-tuples | Abstract |
| » February 26th | Kaave Hosseini | A bilinear Bogolyubov-Ruzsa lemma with poly-logarithmic bounds | Abstract |
| » February 19th | Yasuhide Numata | Title: The strong Lefschetz property for Artin Gorenstein algebras associated to matroids | Abstract |
| » February 12th | Bartosz Walczak | Title: Sparse Kneser graphs are Hamiltonian | Abstract |
| » February 5th | Hang Huang | Title : Syzygies of determinantal thickening via general linear Lie superalgebra | Abstract |
| » January 29th | Bruce Sagan | Combinatorial and algebraic interpretations of Lucas analogues | Abstract |
| » January 15th | Andrew Ahn | Global universality in periodic random plane partitions | Abstract |
| » January 10th at 3pm, APM 6402 | Asaf Ferber | When combinatorics meets Littlewood-Offord theory | Abstract |
| » January 8th at 3pm, APM 6402 | Alan Frieze | On the cover time of two classes of graphs | Abstract |
| » December 17th at 3pm, APM 6402 | Alfredo Hubard | Combinatorial convexity and measures | Abstract |
| » December 11th at 2:00pm in APM 2402 | Gene Kim | A central limit theorem for descents and major indices in fixed conjugacy classes of S_n | Abstract |
| » December 4th in at 5:00pm in APM 6402 | Anna Pun | Catalan functions and k-Schur functions | Abstract |
| » November 27th 3PM, APM 6402 | Radoslav Fulek | The Z_2-genus of complete bipartite graphs | Abstract |
| » November 20th | Cesar Cuenca | q-analogues of representation-theoretic measures | Abstract |
| » November 14th at 2pm, APM 6402 | Clara Shikhelman | Generalized Turan-type problems for random graphs | Abstract |
| » November 14th at 1pm, APM 6402 | Vic Reiner | Cyclic sieving: Old and new (Virtual Combinatorics Colloquium) | Abstract |
| » November 13th at 3pm, APM 6402 | Thao Do | A general incidence bound in high dimensions | Abstract |
| » November 6th | Graham Hawkes | Characterization of queer supercrystals | Abstract |
| » October 30th | Josh Hallam | Whitney duals of partially ordered sets | Abstract |
| » October 23rd | Robert Davis | Identifying the state polytopes of certain combinatorial neural codes | Abstract |
| » October 19th | Christopher O'Neill | Random numerical semigroups | Abstract |
| » October 11th at 1pm, APM 6402 | Joel Spencer | Preferential Attachment when Stable | Abstract |
| » October 2nd | Yesim Karabulut | Unit-graphs and Special Unit-digraphs on Matrix Rings | Abstract |
| 2017-2018 | |||
| DATE | SPEAKER | TITLE | ABSTRACT |
| » October 3rd | Andrzej Dudek | Ramsey properties of random graphs and hypergraphs | Abstract |
| » October 10th | Craig Timmons | Error-Correcting Codes from Finite Geometries | Abstract |
| » October 17th | Ian Charlesworth | Combinatorics in Free Probability | Abstract |
| » October 24th | Jeroen Schillewaert | Small maximal independent sets | Abstract |
| » October 31st | Gabriel Frieden | Promotion and geometric lifting | Abstract |
| » November 7th | Andrew Suk | Ramsey Numbers : Combinatorial and Geometric | Abstract |
| » November 21st | Pawel Pralat | Perfect matchings and Hamiltonian cycles in the preferential attachment model | Abstract |
| » December 5th | Brendon Rhoades | The algebra and geometry of ordered set partitions | Abstract |
| » January 9 at 10am in APM 6402 | Jang Soo Kim | Hook length property of d-complete posets via q-integrals | Abstract |
| » January 9 at 11am in APM 6402 | Soichi Okada | Symplectic Q-functions | Abstract |
| » January 12 at 3pm in APM 6402 | Radoslav Fulek | The Z2 genus of Kuratowski minors | Abstract |
| » February 13 at 2pm in APM 7421 | Andre Kundgen | Nonrepetitive Graph Coloring | Abstract |
| » February 27 | Dhruv Mubayi | Title : Multicolor Sunflowers | Abstract |
| » March 13 | Gene Kim | Distribution of descents in matchings and derangements | Abstract |
| » March 29 4pm, APM 2402 | Penny Haxell | Topological connectedness in combinatorics | Abstract |
| » April 3 9am, APM 6402 | Yan Zhuang | Shuffle-Compatible Permutation Statistics | Abstract |
| » May 15 | Josh Zahl | Breaking the 3/2 barrier for unit distances in three dimensions | Abstract |
| » May 17 3pm APM 6218 | Mike Tait | On the Turán number of theta graphs | Abstract |