기초과학연구원 이산수학그룹
I will introduce Kazhdan-Lusztig polynomials of matroids and survey combinatorial and geometric theories built around them. The focus will be on the conjecture of Gedeon, Proudfoot, and Young that all zeros of the Kazhdan-Lusztig polynomial of a matroid lie on the negative real axis.
Integer Linear Programming (ILP) is among the most successful and general paradigms for solving computationally intractable optimization problems in computer science. ILP is NP-complete, and until recently we have lacked a systematic study of the complexity of ILP through the lens of variable-constraint interactions. This changed drastically in recent years thanks to a series of results that together lay out a …
Program Summer School @ KAIST (August 4-7, 2020) Discussion Weekend (August 8-9, 2020) Workshop @ IBS Science Culture Center (August 10-13, 2020) Website: https://dimag.ibs.re.kr/home/nonlinear/ Organizing Committee Insong Choe (Konkuk U.) Kangjin Han (DGIST) David Hyeon (SNU) Sijong Kwak (KAIST) Yongnam Lee (KAIST) Anton Leykin (Georgia Tech) Sang-il Oum (IBS & KAIST) Frank Sottile (TAMU)
Graph compression or sparsification is a basic information-theoretic and computational question. A major open problem in this research area is whether $(1+\epsilon)$-approximate cut-preserving vertex sparsifiers with size close to the number of terminals exist. As a step towards this goal, we initiate the study of a thresholded version of the problem: for a given parameter $c$, …
Let $X$ be a real random variable; a typical anti-concentration inequality asserts that (under certain assumptions) if an interval $I$ has small length, then $\mathbb{P}(X\in I)$ is small, regardless the location of $I$. Inequalities of this type have found powerful applications in many branches of mathematics. In this talk we will discuss several recent applications …
In 2007, Chepoi, Estellon, and Vaxès conjectured that there exists a universal constant $c>0$ such that the following holds for every positive integers $r$ and $k$, and every planar graph $G$: Either $G$ contains $k$ vertex-disjoint balls of radius $r$, or there is a subset of vertices of size at most $c k$ meeting all …
Combinatorics Workshop (조합론 학술대회) is the biggest annual conference in combinatorics in Korea. It was firstly held in 2004 by the Yonsei University BK21 Research Group. It has been advised by the committee of discrete mathematics of the Korean Mathematical Society since 2013. The aim of this workshop is to bring active researchers with different …
Date August 24, 2020 - August 28, 2020 Arrival: August 23 Sunday. Departure: August 29, Saturday Venue Institute for Basic Science, 55 Expo-ro, Yuseong-gu, Daejeon, South Korea Invited Speakers Julia Böttcher, London School of Economics Boris Bukh, Carnegie Mellon University Amin Coja-Oghlan, Goethe University David Conlon, Caltech Penny Haxell, University of Waterloo Hao Huang, Emory University Jeff Kahn, Rutgers University …
In the early 1980s, Beck proved that, if P is a set of n points in the real plane, and no more than g points of P lie on any single line, then there are $\Omega(n(n-g))$ lines that each contain at least 2 points of P. In 2016, I found a generalization of this theorem, …
Maximum induced matching width, also known as mim-width, is a width parameter for graphs introduced by Vatshelle in 2012. This parameter can be defined over branch decompositions of a graph G, where the width of a vertex partition (X,Y) in G is the size of a maximum induced matching in the bipartite graph induced by …