2024.07.08
09:00 |
Registration
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2024.07.08
10:00 |
Opening
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2024.07.08
10:15 |
Noga Alon: The combinatorics of distance problems
All four birthday boys discovered beautiful connections between combinatorial and geometric results. After a very brief discussion of a (very biased) selection of some of these, I will describe a recent joint work with Matija Bucic and Lisa Sauermann about extremal problems for typical norms, mentioning its connection to questions and results of these four amazing researchers. |
2024.07.08
11:00 |
Coffee Break
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2024.07.08
11:25 |
Martin Balko: Ordered Ramsey numbers: recent progress
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Wouter Cames van Batenburg: Disjoint list-colorings for planar graphs
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Neal Bushaw: Thresholds for Zero-Sum Sequences
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Liping Yuan: On F-convexity
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2024.07.08
11:50 |
Karl Grill: Some Upper Bounds for Property B
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Attila Jung: The Quantitative Fractional Helly theorem
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Sukumar Das Adhikari: Some elementary algebraic and combinatorial methods in the study of zero-sum theorems
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Marianna Bolla: Clustering the Vertices of Sparse Edge-Weighted Graphs via Non-Backtracking Spectra
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2024.07.08
12:15 |
Igor Balla: Small codes and set-coloring Ramsey numbers
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Jan Kynčl: Counterexamples to the thrackle conjecture on higher genus surfaces
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QINGHAI ZHONG: ON A VARIANT OF THE NARKIEWICZ CONSTANT OF FINITE ABELIAN GROUPS
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Vladimir M Blinovsky: Two Recent Proofs of Theorems for matrices
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2024.07.08
12:35 |
Lunch
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2024.07.08
14:00 |
László Lovász: Submodular functions and limits of matroids
Limit theories of graphs were started in the early 2000's, and analogous theories have been developed for posets, permutations, and other combinatorial structures. While trying to develop a limit theory for matroids, we have run across an unexpected connection with analysis, namely potential theory, through the work of Choquet in the 1950's. Our work is still in progress, but I can report on some interesting connections and cross-fertilizations between the combinatorial and analytic theories. This is joint work with Kristóf Bérczi, Márton Borbényi, Boglárka Gehér, András Imolay, Balázs Maga, László Tóth and Dávid Schwarz. |
2024.07.08
14:45 |
Coffee Break
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2024.07.08
15:15 |
Grigory Ivanov: Quantitative Steinitz theorem and polarity.
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Glenn Hurlbert: Recent results on the Holroyd-Talbot Conjecture
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Francesco Di Braccio: Hamilton decompositions of regular tripartite tournaments
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Craig Larson: Conjectures for Paley Graphs
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2024.07.08
15:40 |
Márton Naszódi: Higher rank antipodality
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Kartal Dávid Nagy: FAMILIES WITH LOWER BOUND ON THE SUM OF PAIRWISE INTERSECTIONS OF TRIPLES
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Wangyi Shang: Degree conditions restricted to induced Net and Wounded for hamiltonicity of claw-o-heavy graphs
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Semin Yoo: PALEY-LIKE QUASI-RANDOM GRAPHS ARISING FROM POLYNOMIALS
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2024.07.08
16:00 |
Break
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2024.07.08
16:15 |
Bojan Bašić: Some recent results on the Heesch number in two-dimensional and more-dimensional spaces
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Ruth Lawrence-Naimark: Combinatorial transverse intersection algebra
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Sumin Huang: The maximum sum of the size of all intersections in intersecting families
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Lina Maria Simbaqueba: Sidorenko-type inequalities for Trees
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2024.07.08
16:40 |
Zsolt Lángi: Honeycomb conjecture in normed planes
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Makoto Ozawa: Forbidden complexes for the 3-sphere
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Jiaxi Nie: On Asymptotic Local Turán Problems
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Jae-baek Lee: Disconnected common graphs via supersaturation
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2024.07.09
08:55 |
Tuesday, July 9
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2024.07.09
09:00 |
Jacques Verstraete: Recent progress in Ramsey Theory
The organizing principle of Ramsey theory is that in large mathematical structures, there are relativelynlarge substructures which are homogeneous. This is quantified in combinatorics by the notion of Ramsey numbers r(s,t), which denote the minimum N such that in any red-blue coloring of the edges ofnthe complete graph on N vertices, there exists a red complete graph on s vertices or a blue complete graph on t vertices. While the study of Ramsey numbers goes back almost one hundred years, to early papers of Ramsey and Erdős and Szekeres, the long-standing conjecture of Erdős that r(s,t) has order of magnitude close to t^{s - 1} as t tends to infinity remains open in general. A recent breakthrough by Campos, Griffiths, Morris, and Sahasrabudhe gives an exponential improvement to the diagonal Rasmey numbers. We focus on off-diagonal Ramsey numbers. It took roughly sixty years before the order of magnitude of r(3,t) was determined by Jeong Han Kim, who showed r(3,t) has order of magnitude t^2/(\log t) as t tends to infinity. In this talk, we discuss a variety of new techniques, including the modern method of containers, which lead to a proof of the conjecture of Erdős that r(4,t) is of order close to t^3$. One of the salient philosophies in our approach is that good Ramsey graphs hide inside pseudorandom graphs, and the long-standing emphasis of tackling Ramsey theory from the point of view of purely random graphs is superseded by pseudorandom graphs. Via these methods, we also come close to determining the well-studied related quantities known as Erdős-Rogers functions and discuss related hypergraph coloring problems. Joint work in part with Sam Mattheus, Dhruv Mubayi and David Conlon. |
2024.07.09
09:45 |
Break
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2024.07.09
10:00 |
Jozsef Solymosi: Forbidden patterns among grid-points, hypergraphs and geometric arrangements
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Ferdinand Ihringer: On Boolean Degree 1 Functions (Cameron-Liebler Sets) in Finite Vector Spaces
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Linda Lesniak: On the existence of (r, g, χ)-graphs and cages
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John Gordon Gimbel: Defective Ramsey Numbers for Triangle-free Graphs
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2024.07.09
10:25 |
Aleksa Milojević: Point-variety incidences over arbitrary fields
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Denys Bulavka: A Hilton-Milner theorem for exterior algebras
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Dirk Frettlöh: Perfect colourings of regular graphs
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Domagoj Bradac: The growth rate of multicolor Ramsey numbers of 3-graphs
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2024.07.09
10:45 |
Coffee break
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2024.07.09
11:15 |
Ida Kantor: Metric spaces with many degenerate triangles
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Ting Lan: Degree powers in graphs forbidding broom forests and double brooms
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Vaidyanathan Sivaraman: Chromatic number: Problems, puzzles, and paradoxes
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Thomas Karam: Fourier analysis modulo p on the Boolean cube.
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2024.07.09
11:40 |
Thang Pham: Erdős distinct distances problem, variants, and applications
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Hilal Othman Hama Karim: Generalized planar Turán numbers related to short cycles
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Binlong Li: On the edge-color index of rainbow subgraphs
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Levon Hakob Aslanyan: THE DEADLOCK RESOLVING SETS OF KK-MBF CLASS, AND CARDINALITY ESTIMATES
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2024.07.09
12:05 |
Gabriel Currier: Additive structure in convex translates
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Cory Palmer: A generalized Ramsey-Turán problem
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Yueping Shi: Star colouring of circulant graphs
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Hasmik Artem Sahakyan: IDENTIFICATION OF k-DISTANCE MONOTONE BOOLEAN FUNCTIONS
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2024.07.09
12:25 |
Lunch
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2024.07.09
14:00 |
Andrey Kupavskii: Intersections of interest
Working with Péter Frankl and János Pach in many ways have defined my research path. I wanted to discuss several topics from the joint research with Péter Frankl on intersections and matchings in extremal set theory. I will also cover some recent developments in the field coming from Boolean analysis and spread approximations, and their connections to the work of Péter Frankl and Zoltán Füredi from the 70s and 80s. |
2024.07.09
14:45 |
Coffee Break
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2024.07.09
15:15 |
Maria-Romina Ivan: The Turán Density for Daisies and Hypercubes
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Attila Joó: The Lovász-Cherkassky theorem in infinite graphs
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Yulia Kempner: Violator and Co-Violator Spaces
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Wei-Tian Li: Antimagic Labeling for Subdivisions of Graphs
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2024.07.09
15:40 |
Istvan Tomon: Dedekind's problem in the hypergrid
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Florian Reich: A universal end space theory
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Lamar Chidiac: Positroids are 3-colorable
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Sylwia Cichacz-Przeniosło: On A-cordial trees
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2024.07.09
16:05 |
Alexandru Malekshahian: Counting antichains in the Boolean lattice
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Thilo Krill: Universal graphs with forbidden minors
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Jeremy Quail: Positroid envelope classes and graphic positroids
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Nóra Frankl: Monochromatic infinite sets in Minkowski spaces
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2024.07.10
08:50 |
July 10, Wednesday
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2024.07.10
09:00 |
Alexandr Kostochka: Modifying old ideas to get new results on cycles in hypergraphs
We use an idea of Dirac from 1952 to derive exact degree conditions for the existence of hamiltonian Berge cycles in uniform hypergraphs. We modify another idea of Dirac from 1952 to find exact conditions for the same problem when the hypergraphs are 2-connected. We also modify the Hopping Lemma by Woodall from 1973 to find exact degree conditions for the existence of a spanning jellyfish in a 2-connected graph. The talk is based on joint work with J. Kim, R. Luo and G. McCourt. |
2024.07.10
09:45 |
Break
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2024.07.10
10:00 |
Balázs Keszegh: Saturation saturated
Extremal combinatorics mostly deals with the maximum size structure that has some property (e.g., the maximum number of edges in a graph avoiding a triangle). Saturation counterparts of these problems were studied earlier for graphs and more recently also for many other combinatorial structures. In these we are looking for the minimum size structure that saturates some property, i.e., one that cannot be extended (e.g., the minimum number of edges in a graph avoiding a triangle in which adding any new edge creates a triangle). We survey results of this type, starting with graphs. Extending the unordered case we consider graphs with an order on their vertices, be it linear, cyclic or bipartite linear (a problem equivalent to forbidden 0-1 matrices) and most recently with an order on their edges. Then we survey results related to saturation problems about forbidden subposets in the Boolean poset. We mostly concentrate on the dichotomy phenomenon that is prevalent in these problems: the saturation function is either bounded (not depending on the size of the input) or it is a big function of the input (say, at least linear), further, we try to characterize these two classes. Finally, we show saturation counterparts of several Ramsey-type problems of graphs, posets and point sets, including the problem of Erdős and Szekeres about finding a large convex subset of points in a given set of points. |
2024.07.10
10:45 |
Coffee Break
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2024.07.10
11:15 |
Gergely Kiss: Solutions to the discrete Pompeiu problem and to the finite Steinhaus tiling problem
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Sam Spiro: The random Turán problem
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John Louis Goldwasser: Inducibility in the Hypercube
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Calum Buchanan: A lower bound on the saturation number and a strengthening for triangle-free graphs
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2024.07.10
11:40 |
Dániel Varga: The fractional chromatic number of the plane is at least 4
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Grzegorz Serafin: Asymptotic normality for subgraph count in random (hyper)graphs
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Zelealem Belaineh Yilma: The number of spanning trees in 4-regular simple graphs
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Daniel Johnston: Rainbow Saturation
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2024.07.10
12:05 |
Viola Mészáros: Combinatorial Piercing the Chessboard
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Nemanja Draganić: Optimal Hamilton covers and linear arboricity for random graphs
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David William Matula: "(j x i th prime) adj (i x j th prime)": The Fundamental Relation of Arithmetic
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Anna Taranenko: On vertices of the polytope of polystochastic matrices
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2024.07.10
12:25 |
Lunch
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2024.07.10
14:00 |
Maria Axenovich: Extremal problems in the hypercube
For two (hyper)graphs G and H, the extremal number ex(G, H) is the largest number of edges in an H-free subgraph of the ground graph G. Determining ex(G, H) remains a challenge in general, evennwhen G is a complete graph Kn. However, in this case we know exactly what (hyper)graphs H have a positive or zero Turán density π(H), where π(H) = limn→∞ ex(Kn, H)/||Kn||. When the ground graph G is the hypercube Q of dimension n, we don’t even have such a characterisation. In this talk, I will present what we know about ex(Q, H) and how this extremal number relates to the classical extremal numbers of hypergraphs. |
2024.07.10
14:45 |
Coffee Break
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2024.07.10
15:15 |
Abhishek Methuku: New methods for expanders and their applications
In this talk we will present new methods and tools for expanders and discuss how they can be used to make progress towards several longstanding open problems. Based on joint works with Bradac, Chakraborti, Janzer, Letzter, Montgomery and Sudakov. |
2024.07.10
18:30 |
Conference dinner
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2024.07.11
07:55 |
Thursday, July 11
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2024.07.11
09:30 |
Jian Wang: The modified shifting method and intersecting families with covering number three
The shifting method, invented by Erdős, Ko and Rado, is a powerful tool in extremal set theory. Many nice properties are maintained by the shifting operator, such as, intersecting, cross-intersecting and matching number at most s. However, if there is some property that might be destroyed by shifting, then the shifting method often can not be used. Recently, Frankl proposed a modified version of the shifting method called shifted ad extremis, which extends the power of the shifting method. By applying this method, we reprove some classical results with better bounds on n. In particular we determine the maximum size that an intersecting k-graph F with covering number at least three can have if k ≥ 7, n ≥ 2k, This was already done by Frankl in 1978 subject to exponential constraints on n with respect to k. |
2024.07.11
10:15 |
Break
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2024.07.11
10:30 |
Lajos Hajdu: On arithmetic graphs
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Ron Holzman: Triangle-free triple systems
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Matej Stehlik: Criticality in Sperner’s lemma
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Aleksa Džuklevski: Some new results concerning polymorphic and σ-morphic monotiles
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2024.07.11
10:50 |
Coffee Break
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2024.07.11
11:15 |
Peter van Hintum: Ruzsa's discrete Brunn-Minkowski inequality and locality in sumsets.
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Zoltan Lorant Nagy: Friendly partitions of regular graphs
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Sam Adriaensen: Circle geometries: Intersecting families and association schemes
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Pjotr Buys: Reconfiguration of Independent Transversals
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2024.07.11
11:40 |
Marius Tiba: Sharp stability for the Brunn-Minkowski inequality for arbitrary sets
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Puck Rombach: Odd Covers
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Kristina Ago: Axiomatic geometry of Hilbert through the lens of a combinatorist
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Eng Keat Hng: Characterising flip process rules with the same trajectories
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2024.07.11
12:05 |
Fei Peng: Coprime mappings and lonely runners
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Alexander Clifton: Recent Progress on the Odd Cover Problem
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Zhihan Jin: The Helly Property for the Hamming Balls
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Anna Limbach: Graphon Branching Processes and Fractional Isomorphism
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2024.07.11
12:25 |
Lunch
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2024.07.11
14:00 |
Younjin Kim: Problems on Extremal Combinatorics
Extremal combinatorics aims to determine or estimate the maximum or minimum possible cardinality of a collection of finite objects (such as sets, graphs, numbers, vectors, etc.) that satisfy certain requirements. I am particularly interested in Turán-type problems for hypergraphs and graphs. In this talk, I will introduce Erdős-Shelah Conjecture (1972), which I have worked on in collaboration with other coauthors, including significant contributions made with Professor Zoltán Füredi. Additionally, I will discuss Alon-Babai-Suzuki Conjecture (1991), Erdős-Sós Conjecture (1979), and Erdős Nested Cycle Conjecture (1976). |
2024.07.11
14:45 |
Coffee Break
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2024.07.11
15:15 |
Arsenii Sagdeev: Canonical theorems in Euclidean Ramsey theory
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Seonghyuk Im: Dirac's theorem for linear hypergraphs
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András Pongrácz: The maximum clique query problem
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Luke Collins: CHORDS IN LONGEST CYCLES
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2024.07.11
15:40 |
Kenneth Moore: Plane colorings and arithmetic progressions
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Nathan Lemons: Coloring Hypergraphs
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Erfei Yue: Results on Bollobás set-pair systems
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Shenggui Zhang: The absence of monochromatic triangles implies various properly colored spanning trees
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2024.07.11
16:05 |
Alexander Natalchenko: Monochromatic quadrilaterals in the max-norm plane
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Chaya Keller: Hitting and coloring subsets in geometric hypergraphs
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Georgios Kontogeorgiou: Small weakly separating path systems for complete graphs
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Henry Liu: Rainbow cycles through specified vertices
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2024.07.12
00:00 |
Friday, July 12
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2024.07.12
09:00 |
Géza Tóth: Crossing Lemma for multigraphs
Let G be a simple graph with n vertices and e ≥ 4n edges. According to the Crossing Lemma, the number of crossings in any drawing of G is at least c{e^3\over n^2}, for a positive constant c. This bound cannot be improved apart from the value of c. There is no such statement for multigraphs in general. We investigate under what conditions does the satement of the Crossing Lemma, or a similar statement holds for multigraphs. In particular, we show that if the ``lens'' enclosed by every pair of parallel edges contains at least one vertex and adjacent edges do not cross, then the original statement holds. A similar, but weaker bound holds if we only assume that no two edges are homotopic, that is, no two parallel edges can be continuously transformed into each other without passing through an vertex. Joint work with M. Kaufmann, J. Pach, G. Tardos, T. Ueckerdt. |
2024.07.12
09:45 |
Break
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2024.07.12
10:00 |
Anurag Bishnoi: Covering grids with multiplicity
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Miklós Ruszinkó: Linear Turán numbers
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Ofelia Cepeda Camargo: A CHARACTERIZATION OF THE SEMITWIN DIGRAPH
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Lorenzo Sauras Altuzarra: On closed forms of C-recursive integer sequences
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2024.07.12
10:25 |
John R. Schmitt: Repeatedly applying the Combinatorial Nullstellensatz for Zero-sum Grids to Martin Gardner’s minimum no-3-in-a-line problem
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Nika Salia: Linear three-uniform hypergraphs with no Berge path of given length
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Gaurav Kucheriya: Orientations of graphs with at most one directed path between every pair of vertices
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Johann A Makowsky: Supercongruences and MC-finiteness of Integer Sequences.
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2024.07.12
10:45 |
Coffee break
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2024.07.12
11:15 |
Filip Kučerák: Uniform Turán densities of 3-uniform hypergraphs.
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Felipe Hernández-Lorenzana: A generalization of properly colored paths and cycles in edge-colored graphs
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Ararat Harutyunyan: Some problems and results on large acyclic sets in digraphs
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2024.07.12
11:40 |
Kalina Petrova: The Hamilton space of pseudorandom graphs
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Carlos Alberto Vilchis-Alfaro: Trails in arc-colored digraphs with restriction in the color transitions
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Qiuzhenyu Tao: The structure of directed 1-separations in directed graphs with cyclic torsoids
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2024.07.12
12:05 |
Attila Sali: Stability results for forbidden configurations
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María del Rocío Sánchez López: Colored reachability in 3-quasi-transitive digraphs
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Yandong Bai: Vertex-disjoint cycles of different lengths in tournaments
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2024.07.12
12:25 |
Lunch
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2024.07.12
14:00 |
Jacob Fox: Strings and Drawing
The study of extremal problems for topological graphs and the study of intersection patterns of curves has a rich history. In this talk, I will highlight recent progress and longstanding open problems. It will be clear that János Pach's influence on the field is pervasive. |