Zhihan Jin (金之涵), The Helly number of Hamming balls and related problems
Room B332 IBS (기초과학연구원)We prove the following variant of Helly’s classical theorem for Hamming balls with a bounded radius. For
10 events found.
Gábor Tardos, Extremal theory of 0-1 matrices
Room B332 IBS (기초과학연구원)We say that a 0-1 matrix A contains another such matrix (pattern) P if P can be obtained from a submatrix of A by possibly changing a few 1 entries to 0. The main question of this theory is to estimate the maximal number of 1 entries in an n by n 0-1 matrix NOT …
Mathias Schacht, Canonical colourings in random graphs
Room B332 IBS (기초과학연구원)Rödl and Ruciński established Ramsey's theorem for random graphs. In particular, for fixed integers
Kyeongsik Nam (남경식), Random walks on percolation
Room B332 IBS (기초과학연구원)In general, random walks on fractal graphs are expected to exhibit anomalous behaviors, for example heat kernel is significantly different from that in the case of lattices. Alexander and Orbach in 1982 conjectured that random walks on critical percolation, a prominent example of fractal graphs, exhibit mean field behavior; for instance, its spectral dimension is …
Colin Geniet, Permutations, patterns, and twin-width
Room B332 IBS (기초과학연구원)This talk will first introduce combinatorics on permutations and patterns, presenting the basic notions and some fundamental results: the Marcus-Tardos theorem which bounds the density of matrices avoiding a given pattern, and the Guillemot-Marx algorithm for pattern detection using the notion now known as twin-width. I will then present a decomposition result: permutations avoiding a …
Felix Christian Clemen, Triangles in the Plane
Room B332 IBS (기초과학연구원)A classical problem in combinatorial geometry, posed by Erdős in 1946, asks to determine the maximum number of unit segments in a set of
Michał Pilipczuk, Monadic stability and monadic dependence
Room B332 IBS (기초과학연구원)We will give an overview of the recent attempts of building a structure theory for graphs centered around First-Order transductions: a notion of containment inspired by finite model theory. Particularly, we will speak about the notions of monadic dependence and monadic stability, their combinatorial characterizations, and the developments on the algorithmic front.
IBS-DIMAG Workshop on Topology and Combinatorics
Room B332 IBS (기초과학연구원)The IBS-DIMAG Workshop on Topology and Combinatorics will be held on November 11, 2024 at Room B332, Institute for Basic Science (IBS), Daejeon, South Korea. Invited Speakers (tentative) Karim Adiprasito (Jussieu Institute of Mathematics) Minho Cho조민호 (IBS Extremal Combinatorics and Probability Group) Niloufar Fuladi (INRIA Center of Université de Lorraine) Minki Kim김민기 (GIST) Dohyeon Lee이도현 (KAIST & …
Karim Adiprasito, Ehrhart theory revisited: Algebraic aspects, unimodality and more
Room B332 IBS (기초과학연구원)Ehrhart theory is the study of lattice polytopes, specifically aimed at understanding how many lattice points are inside dilates of a given lattice polytope, and the study has a wide range of connections ranging from coloring graphs to mirror symmetry and representation theory. Recently, we introduced new algebraic tools to understand this theory, and resolve …
Eng Keat Hng, Graphon branching processes and fractional isomorphism
Room B332 IBS (기초과학연구원)In 2005, Bollobás, Janson and Riordan introduced and extensively studied a general model of inhomogeneous random graphs parametrised by graphons. In particular, they studied the emergence of a giant component in these inhomogeneous random graphs by relating them to a broad collection of inhomogeneous Galton-Watson branching processes. Fractional isomorphism of finite graphs is an important …