## Past One-Day Meetings

I started the annual One-Day Meeting in Combinatorics at UCL in 1999.
It ran there every year until 2005, after which it moved to Oxford.
Throughout its life, it has received wonderful support from the London
Mathematical Society and the British Combinatorial Committee.

Here is a list of speakers and titles for past meetings.

**2023**

**Maya Stein (University of Chile),**
*Antidirected trees in oriented graphs*

**Mathias Schacht (Hamburg),**
*Canonical colourings in random graphs*

**János Pach (Rényi Institute, Hungary and IST Austria),**
*Grasshoppers and linear algebra*

**Marthe Bonamy (Bordeaux),**
*Separating edges with few paths*

**Mehtaab Sawhney (Cambridge/MIT),**
*On perfectly friendly bisections of random graphs*

**Julian Sahasrabudhe (Cambridge),**
*An exponential improvement for diagonal Ramsey*

**2022**

**Gabor Lugosi (Barcelona),**
*Root finding and broadcasting in recursive trees and dags*

**Gal Kronenberg (Oxford),**
*Partitioning cubic graphs into isomorphic linear forests*

**Paul Balister (Oxford),**
*Monotone cellular automata*

**Julia Wolf (Cambridge),**
*Irregular triads in 3-uniform hypergraphs*

**David Wood (Monash),**
*Universality in minor-closed graph classes*

**2020-2021**

The regular One-Day Meeting was suspended for this period. However, in June 2021, there was a special Round the World Relay in Combinatorics, with 22 seminars from around the world.

**2019**

**Vida Dujmovic (Ottawa),**
*Layered H-partitions with applications*

**Louis Esperet (Grenoble),**
*Exact distance colouring in trees*

**Perla Sousi (Cambridge),**
*Random walk on dynamical percolation*

**Remco van der Hofstad (Eindhoven),**
*Hypercube percolation*

**Martin Grohe (Aachen),**
*The combinatorial and descriptive complexity of identifying a graph*

**2018**

**Benny Sudakov (Zurich),**
*Rainbow structures, Latin squares & graph decompositions*

**Paul Wollan (Rome),**
*A grid theorem for vertex minors and rankwidth*

**Maria Chudnovsky (Princeton),**
*Coloring graphs with forbidden induced subgraphs*

**Kristina Vušković (Leeds),**
*Clique cutsets beyond chordal graphs*

**Daniel Kral (University of Warwick),**
*Graph limits and extremal combinatorics*

**2017**

**Christina Goldschmidt (Oxford),**
*Critical random graphs with i.i.d. random degrees having power-law tails*

**Bruce Reed (CNRS/McGill),**
*The typical structure of graphs in a hereditary family*

**Daniela Kuhn (Birmingham),**
*Approximately counting list H-colourings*

**David Wood (Monash),**
*Improper relaxations of Hadwiger's Conjecture*

**Paul Seymour (Princeton),**
*Rainbow paths*

**2016**

**Mihyun Kang (Graz),**
*Jigsaw percolation on random hypergraphs*

**János Pach (Budapest/Lausanne),**
*Distinct distances: Quo vadis?*

**Leslie Goldberg (Oxford),**
*Approximately counting list H-colourings*

**Gábor Tardos (Budapest),**
*Extremal theory of ordered graphs*

**Penny Haxell (Waterloo),**
*Matchings in tripartite hypergraphs*

**2015**

**Amin Coja-Oghlan (Goethe University, Frankfurt),**
*Random graph coloring*

**Louigi Addario-Berry (Montreal),**
*Most trees are short and fat*

**Maria Chudnovsky (Princeton),**
*Coloring square-free perfect graphs*

**Andrew Thomason (Cambridge),**
*Quick and Easy containers*

**Paul Seymour (Princeton),**
*Consecutive holes*

**2014**

**Rob Morris (IMPA),**
*Counting sparse H-free graphs*

**Angelika Steger (ETH Zurich),**
*Ramsey theorems for random structures*

**Jacob Fox (MIT),**
*Combinatorics of permutations*

**Jeff Kahn (Rutgers),**
*A little more on "sparse random"*

**Gil Kalai (Jerusalem),**
*Influence, thresholds, and noise sensitivity*

**2013**

**Peter Keevash (QMUL),**
*Dynamic concentration of the triangle-free process*

**Amin Coja-Oghlan (Frankfurt),**
*Chasing the k-SAT threshold*

**Jean-Sébastien Sereni (CNRS),**
*Questions (and answers) about fractional colourings*

**Penny Haxell (Waterloo),**
*Morphing planar graph drawings*

**Ben Green (Cambridge),**
*Counting sumsets and the clique number of random Cayley graphs, revisited*

**2012**

**Jarik Nesetril (Prague),**
*Subgraph statistics for sparse graphs*

**Benny Sudakov (UCLA),**
*Induced matchings, arithmetic progressions and communication*

**Louigi Addario-Berry (Montreal),**
*The spectrum of random lifts*

**Jacob Fox (MIT) ,**
*Two extensions of Ramsey's theorem*

**Béla Bollobás (Cambridge/Memphis),**
*Bootstrap percolation in all dimensions*

**2011**

**Leslie Goldberg (Liverpool),**
*Estimating the partition function of the ferromagnetic Ising model on a regular matroid*

**Stéphan Thomassé (Montpellier),**
*Applications of VC-dimension to graphs and hypergraphs*

**Francisco Santos (Cantabria),**
*Counter-examples to the Hirsch conjecture*

**Maria Chudnovsky (Columbia),**
*Vertex-disjoint paths in tournaments*

**Paul Seymour (Princeton),**
*Colouring tournaments*

**2010**

**Mark Jerrum (QMUL),** *The ferromagnetic Potts model: phase transition,
gadgets and computational complexity*

**David Gamarnik (MIT),** *A combinatorial approach to the interpolation
method and scaling limits in sparse random graphs*

**Benny Sudakov (UCLA),** *Ramsey numbers of graphs and hypergraphs*

**Günter M. Ziegler (Berlin),** *Some centrally-symmetric polytopes
derived from perfect graphs*

**Adrian Bondy (Lyon/Paris),** *Switching Reconstruction*

**2009**

**Penny Haxell (Waterloo), ***Packing and covering
tetrahedra*

**Michael Drmota (Vienna), ***The degree distribution of random planar
graphs*

**Mathias Schacht (Berlin)***, Regularity lemmas for (hyper)graphs*

**Kristina Vuskovic (Leeds)***, Structure of graph classes closed under
taking induced subgraphs*

Miklós Simonovits (Budapest)**, ***
Stability methods, extremal graph theory, and some other applications*

**2008**

**Michael Krivelevich (Tel Aviv),** *Avoider-Enforcer: the rules of the
game*

**Andrew Thomason (Cambridge),** *Extremal graph theory with colours*

Monique Laurent (CWI Amsterdam), *Real solving polynomial equations with
semidefinite programming*

Colin McDiarmid (Oxford), *Random graphs from a minor-closed class*

Stefanie Gerke (Royal Holloway), *Sequences with changing dependencies*

**2007**

**Nati Linial (Jerusalem)***,
Combinatorial and computational applications of factorization norms*

Graham Brightwell (LSE)*, Order-invariant poset processes*

**Jaroslav Nešetřil (Prague)**, *Dualities for finite structures*

**Bruce Reed (McGill)**, *(1,2)-colourings of graphs*

**Philippe Flajolet (INRIA), ***Boltzmann sampling and random
generation of combinatorial structures*

**2006**

**Bert Gerards (CWI Amsterdam), ***Towards a structure
theory for matrices and matroids*

**Marc Noy (Univ. Politécnica de Catalunya)***,
Counting labelled planar graphs*

**Peter Cameron (QMUL)**, *Orbital chromatic roots*

**Angelika Steger (ETH Zürich)***, Extremal subgraphs of random graphs*

Alan Frieze (Carnegie Mellon)*, Anti-Ramsey properties of random graphs*

**2005**

**Stéphan Thomassé (Lyon)***, Dense triangle-free
graphs are four chromatic*

**Jeffrey Steif (Chalmers),*** An application of analysis to
theoretical computer science: Coin flipping protocols*

**Günter Ziegler (Berlin)***, Matrices, Gale diagrams, and polyhedral
surfaces of high genus*

Alexander Schrijver (Amsterdam)*, New code bounds from the Terwilliger
algebra and semidefinite programming*

Dominic Welsh (Oxford)*, Random graphs from planar and other addable
families*

**2004**

**Svante Janson (Uppsala)**, *Random cuttings and
records in random and deterministic trees*

**Oliver Riordan (Cambridge)***, The small giant component in
scale-free random graphs*

**Penny Haxell (Waterloo)**, *On a Ramsey problem*

**Boris Aronov (New York)***, The Crossing Lemma and its Applications*

János Pach (New York/Budapest), *The minimum number of directions
determined by n points in 3-space*

**2003**

**Imre Leader (Cambridge)**, *Forbidden distances in
the reals*

**Gregory Sorkin (IBM)***, Random MAX SAT, random MAX CUT, and their
phase transitions*

Michele Conforti (Padova), *Coloring of matrices and integer polyhedra*

**Angelika Steger (Munich)**, *Extremal random graph theory*

Jaroslav Nešetřil (Prague), *On Ramsey classes and homogeneous structures*

**2002**

**Bill Jackson (Goldsmiths)**,* The zero distribution
of chromatic and flow polynomials of graphs*

**Jorge Ramirez Alfonsin (Paris)***, About a problem of McMullen on
projective equivalences of polytopes*

**Imre Bárány (UCL/Budapest)**, *A fractional Helly theorem for convex
lattice sets*

**Marek Karpinski (Bonn)**, *Approximating Bounded Degree Instances of
NP-hard Problems*

**Zoltan Füredi (Illinois/Budapest)**, *Superimposed codes*

**2001**

**Reinhard Diestel (Hamburg), ***Path-width,
tree-width, and beyond*

Gábor Tardos (Budapest), *On roughly transitive amenable graphs and
harmonic Dirichlet functions*

Leslie Goldberg (Warwick), *On the relative complexity of approximate
counting problems*

Jirí Matoušek (Prague), *A combinatorial proof of Kneser's conjecture*

**Gil Kalai (Jerusalem)**, *Fourier-Walsh Coefficients of Boolean
Functions*

**2000**

**Alan Sokal (NYU)**, *Chromatic polynomials, Potts
models and all that*

**Martin Dyer (Leeds)***, Counting graph homomorphisms (exactly and
approximately)*

**Colin McDiarmid (Oxford)**, *Graph imperfection*

Miklos Laczkovich (Budapest), *Configurations with rational angles*

Hans-Jürgen Prömel (Berlin),* On the structure of clique-free graphs*

**1999**

**Dominic Welsh (Oxford)**, *Counting
Forests and Related Problems*

**Andrew Thomason (Cambridge)**,* The Structure of Hereditary Graph
Properties*

**Graham
Brightwell (LSE)**, *Algorithmic Aspects of Partially Ordered Sets*

**Mark Jerrum (Edinburgh)***, How (Not) to Sample Random
Unlabelled Structures*

**János Pach (Math Institute Hungarian Acad Sci/Courant Institute)**, *
Crossing Numbers of Graphs*