Ben Lund, Maximal 3-wise intersecting families
A family $\mathcal F$ of subsets of {1,2,…,n} is called maximal k-wise intersecting if every collection of at most k members from $\mathcal F$ has a common element, and moreover, …
10 events found.
Discrete Math Seminar
Events
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Room B232 IBS (기초과학연구원)
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Jaehoon Kim (김재훈), 2-complexes with unique embeddings in 3-space
Room B232 IBS (기초과학연구원)A well-known theorem of Whitney states that a 3-connected planar graph admits an essentially unique embedding into the 2-sphere. We prove a 3-dimensional analogue: a simply-connected 2-complex every link graph …
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Casey Tompkins, Ramsey numbers of Boolean lattices
Room B232 IBS (기초과학연구원)The poset Ramsey number $R(Q_{m},Q_{n})$ is the smallest integer $N$ such that any blue-red coloring of the elements of the Boolean lattice $Q_{N}$ has a blue induced copy of $Q_{m}$ …
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Seonghyuk Im (임성혁), Large clique subdivisions in graphs without small dense subgraphs
Room B232 IBS (기초과학연구원)What is the largest number $f(d)$ where every graph with average degree at least $d$ contains a subdivision of $K_{f(d)}$? Mader asked this question in 1967 and $f(d) = \Theta(\sqrt{d})$ …
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Eun-Kyung Cho (조은경), Independent domination of graphs with bounded maximum degree
Room B232 IBS (기초과학연구원)The independent domination number of a graph $G$, denoted $i(G)$, is the minimum size of an independent dominating set of $G$. In this talk, we prove a series of results regarding …
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Tuan Tran, Exponential decay of intersection volume with applications on list-decodability and sphere-covering bounds
Room B232 IBS (기초과학연구원)We give some natural sufficient conditions for balls in a metric space to have small intersection. Roughly speaking, this happens when the metric space is (i) expanding and (ii) well-spread, …
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Seunghun Lee (이승훈), Transversals and colorings of simplicial spheres
Room B232 IBS (기초과학연구원)Motivated from the surrounding property of a point set in $\mathbb{R}^d$ introduced by Holmsen, Pach and Tverberg, we consider the transversal number and chromatic number of a simplicial sphere. As …
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Andreas Holmsen, Some recent results on geometric transversals
Room B232 IBS (기초과학연구원)A geometric transversal to a family of convex sets in $\mathbb R^d$ is an affine flat that intersects the members of the family. While there exists a far-reaching theory concerning …
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Jaehyeon Seo (서재현), A rainbow Turán problem for color-critical graphs
Room B232 IBS (기초과학연구원)For given $k$ graphs $G_1,\dots, G_k$ over a common vertex set of size $n$, what conditions on $G_i$ ensures a 'colorful' copy of $H$, i.e. a copy of $H$ containing …
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O-joung Kwon (권오정), Reduced bandwidth: a qualitative strengthening of twin-width in minor-closed classes (and beyond)
Room B232 IBS (기초과학연구원)In a reduction sequence of a graph, vertices are successively identified until the graph has one vertex. At each step, when identifying $u$ and $v$, each edge incident to exactly …