Qizhong Lin, Two classical Ramsey-Turán numbers involving triangles
Zoom ID: 224 221 2686 (ibsecopro)In 1993, Erdős, Hajnal, Simonovits, Sós and Szemerédi proposed to determine the value of Ramsey-Turán density
10 events found.
Seminars and Colloquiums
Tianchi Yang, On the maximum number of edges in k-critical graphs
Room B332 IBS (기초과학연구원)In this talk, we will discuss the problem of determining the maximum number of edges in an n-vertex k-critical graph. A graph is considered k-critical if its chromatic number is k, but any proper subgraph has a chromatic number less than k. The problem remains open for any integer k ≥ 4. Our presentation will …
István Tomon, Configurations of boxes
Room B332 IBS (기초과학연구원)Configurations of axis-parallel boxes in
Jie Han, Spanning trees in expanders
Zoom ID: 224 221 2686 (ibsecopro)We consider the spanning tree embedding problem in dense graphs without bipartite holes and sparse graphs. In 2005, Alon, Krivelevich and Sudakov asked for determining the best possible spectral gap forcing an
James Davies, Two structural results for pivot-minors
Room B332 IBS (기초과학연구원)Pivot-minors can be thought of as a dense analogue of graph minors. We shall discuss pivot-minors and two recent results for proper pivot-minor-closed classes of graphs. In particular, that for every graph H, the class of graphs containing no H-pivot-minor is 𝜒-bounded, and also satisfies the (strong) Erdős-Hajnal property.
Shin-ichiro Seki, On the extension of the Green-Tao theorem to number fields
Zoom ID: 897 6822 0619 (ibsecopro) [04/19 only]In 2006, Tao established the Gaussian counterpart of the celebrated Green-Tao theorem on arithmetic progressions of primes. In this talk, I will explain the extension of Tao's theorem and the Green-Tao theorem to the case of general number fields. Our combinatorial tool is the relative hypergraph removal lemma by Conlon-Fox-Zhao. I will discuss the difficulties …
Hyunwoo Lee (이현우), On perfect subdivision tilings
Room B332 IBS (기초과학연구원)For a given graph
Rob Morris, Ramsey theory: searching for order in chaos
Room 1501, Bldg. E6-1, KAISTIn many different areas of mathematics (such as number theory, discrete geometry, and combinatorics), one is often presented with a large "unstructured" object, and asked to find a smaller "structured" object inside it. One of the earliest and most influential examples of this phenomenon was the theorem of Ramsey, proved in 1930, which states that …
Rob Morris, An exponential improvement for diagonal Ramsey
Room B332 IBS (기초과학연구원)The Ramsey number
Jozef Skokan, Separating the edges of a graph by a linear number of paths
Room B332 IBS (기초과학연구원)Recently, Letzter proved that any graph of order n contains a collection P of