BEGIN:VCALENDAR
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PRODID:-//Discrete Mathematics Group - ECPv6.15.20//NONSGML v1.0//EN
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X-WR-CALNAME:Discrete Mathematics Group
X-ORIGINAL-URL:https://dimag.ibs.re.kr
X-WR-CALDESC:Events for Discrete Mathematics Group
REFRESH-INTERVAL;VALUE=DURATION:PT1H
X-Robots-Tag:noindex
X-PUBLISHED-TTL:PT1H
BEGIN:VTIMEZONE
TZID:Asia/Seoul
BEGIN:STANDARD
TZOFFSETFROM:+0900
TZOFFSETTO:+0900
TZNAME:KST
DTSTART:20220101T000000
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END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230404T163000
DTEND;TZID=Asia/Seoul:20230404T173000
DTSTAMP:20260419T080041
CREATED:20230116T010354Z
LAST-MODIFIED:20240707T073814Z
UID:6667-1680625800-1680629400@dimag.ibs.re.kr
SUMMARY:István Tomon\, Configurations of boxes
DESCRIPTION:Configurations of axis-parallel boxes in $\mathbb{R}^d$ are extensively studied in combinatorial geometry. Despite their perceived simplicity\, there are many problems involving their structure that are not well understood. I will talk about a construction that shows that their structure might be more complicated than people conjectured.
URL:https://dimag.ibs.re.kr/event/2023-04-04/
LOCATION:Room B332\, IBS (기초과학연구원)
CATEGORIES:Discrete Math Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230406T100000
DTEND;TZID=Asia/Seoul:20230406T110000
DTSTAMP:20260419T080041
CREATED:20230118T233830Z
LAST-MODIFIED:20240707T073746Z
UID:6691-1680775200-1680778800@dimag.ibs.re.kr
SUMMARY:Jie Han\, Spanning trees in expanders
DESCRIPTION: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 $(n\,d\,\lambda)$-graph to be $T(n\, \Delta)$-universal. In this talk\, we introduce our recent work on this conjecture.
URL:https://dimag.ibs.re.kr/event/2023-04-06/
LOCATION:Zoom ID: 224 221 2686 (ibsecopro)
CATEGORIES:Virtual Discrete Math Colloquium
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230411T163000
DTEND;TZID=Asia/Seoul:20230411T173000
DTSTAMP:20260419T080041
CREATED:20230220T150254Z
LAST-MODIFIED:20240705T165050Z
UID:6812-1681230600-1681234200@dimag.ibs.re.kr
SUMMARY:James Davies\, Two structural results for pivot-minors
DESCRIPTION: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.
URL:https://dimag.ibs.re.kr/event/2023-04-11/
LOCATION:Room B332\, IBS (기초과학연구원)
CATEGORIES:Discrete Math Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20230417
DTEND;VALUE=DATE:20230425
DTSTAMP:20260419T080041
CREATED:20221108T013322Z
LAST-MODIFIED:20240705T171116Z
UID:6435-1681689600-1682380799@dimag.ibs.re.kr
SUMMARY:MATRIX-IBS Workshop: Structural Graph Theory Downunder III
DESCRIPTION:Website: https://www.matrix-inst.org.au/events/structural-graph-theory-downunder-iii/ \nProgram Description:  \nThis program\, jointly organised by MATRIX and the Discrete Mathematics Group of the Korean Institute for Basic Science (IBS)\, builds on the “Structural Graph Theory Downunder” programs held at MATRIX in 2019 and 2022. In this short intensive workshop\, mathematicians from across the globe will come together to work on open problems in structural graph theory. The focus will be on graph colouring\, graph minors\, induced subgraphs\, and graph product structure theory. The majority of the time will be allocated to collaborative research\, with only a few talks describing recent advances. The goal is to create an environment where mathematicians at all career stages work side-by-side. We anticipate that open problems will be solved\, and lasting collaborations will be initiated. \nConfirmed Participants: \nRutger Campbell (Institute for Basic Science\, Korea)\nLinda Cook (Institute for Basic Science\, Korea)\nJames Davies (University of Cambridge\, UK)\nMarc Distel (Monash University\, Australia)\nZdeněk Dvořák (Charles University\, Czech Republic)\nBryce Frederickson (Emory University\, USA)\nAntónio Girão (University of Oxford\, UK)\nPascal Gollin (Institute for Basic Science\, Korea)\nKevin Hendrey (Institute for Basic Science\, Korea)\nRobert Hickingbotham (Monash University\, Australia)\nFreddie Illingworth (University of Oxford\, UK)\nO-joung Kwon (Hanyang University\, Korea)\nFlorian Lehner (University of Auckland\, New Zealand)\nAnita Liebenau (UNSW\, Australia)\nChun-Hung Liu (Texas A&M\, USA)\nRose McCarty (Princeton University\, USA)\nLukas Michel (University of Oxford\, UK)\nSang-il Oum (Institute for Basic Science and KAIST\, Korea)\nMichael Savery (University of Oxford\, UK)\nAlex Scott (University of Oxford\, UK)\nRaphael Steiner (ETH Zurich\, Switzerland)\nJane Tan (University of Oxford\, UK)\nSebastian Wiederrecht (Institute for Basic Science\, Korea)\nDavid Wood (Monash University\, Australia)\nLiana Yepremyan (Emory University\, USA)
URL:https://dimag.ibs.re.kr/event/2023-04-17/
LOCATION:MATRIX\, Australia
CATEGORIES:Workshops and Conferences
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230419T163000
DTEND;TZID=Asia/Seoul:20230419T173000
DTSTAMP:20260419T080041
CREATED:20230301T064147Z
LAST-MODIFIED:20240705T165047Z
UID:6852-1681921800-1681925400@dimag.ibs.re.kr
SUMMARY:Shin-ichiro Seki\, On the extension of the Green-Tao theorem to number fields
DESCRIPTION: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 that arise in the case of general number fields and an application of our results to prime representations by binary quadratic forms. This is based on joint work with Wataru Kai\, Masato Mimura\, Akihiro Munemasa\, and Kiyoto Yoshino.
URL:https://dimag.ibs.re.kr/event/2023-04-19/
LOCATION:Zoom ID: 897 6822 0619 (ibsecopro) [04/19 only]
CATEGORIES:Virtual Discrete Math Colloquium
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230425T163000
DTEND;TZID=Asia/Seoul:20230425T173000
DTSTAMP:20260419T080041
CREATED:20230315T025543Z
LAST-MODIFIED:20240707T073739Z
UID:6905-1682440200-1682443800@dimag.ibs.re.kr
SUMMARY:Hyunwoo Lee (이현우)\, On perfect subdivision tilings
DESCRIPTION:For a given graph $H$\, we say that a graph $G$ has a perfect $H$-subdivision tiling if $G$ contains a collection of vertex-disjoint subdivisions of $H$ covering all vertices of $G.$ Let $\delta_{sub}(n\, H)$ be the smallest integer $k$ such that any $n$-vertex graph $G$ with minimum degree at least $k$ has a perfect $H$-subdivision tiling. For every graph $H$\, we asymptotically determined the value of $\delta_{sub}(n\, H)$. More precisely\, for every graph $H$ with at least one edge\, there is a constant $1 < \xi^*(H)\leq 2$ such that $\delta_{sub}(n\, H) = \left(1 - \frac{1}{\xi^*(H)} + o(1) \right)n$ if $H$ has a bipartite subdivision with two parts having different parities. Otherwise\, the threshold depends on the parity of $n$.
URL:https://dimag.ibs.re.kr/event/2023-04-25/
LOCATION:Room B332\, IBS (기초과학연구원)
CATEGORIES:Discrete Math Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230427T161500
DTEND;TZID=Asia/Seoul:20230427T171500
DTSTAMP:20260419T080041
CREATED:20230321T001954Z
LAST-MODIFIED:20240705T164205Z
UID:6930-1682612100-1682615700@dimag.ibs.re.kr
SUMMARY:Rob Morris\, Ramsey theory: searching for order in chaos
DESCRIPTION:In 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 if n = n(k) is large enough\, then in any red-blue colouring of the edges of the complete graph on n vertices\, there exists a monochromatic clique on k vertices. In this talk I will discuss some of the questions\, ideas\, and new techniques that were inspired by this theorem\, and present some recent progress on one of the central problems in the area: bounding the so-called “diagonal” Ramsey numbers. Based on joint work with Marcelo Campos\, Simon Griffiths and Julian Sahasrabudhe.
URL:https://dimag.ibs.re.kr/event/2023-04-27/
LOCATION:Room 1501\, Bldg. E6-1\, KAIST
CATEGORIES:Colloquium
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