BEGIN:VCALENDAR
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PRODID:-//Discrete Mathematics Group - ECPv6.15.20//NONSGML v1.0//EN
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METHOD:PUBLISH
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:20190101T000000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20201005T170000
DTEND;TZID=Asia/Seoul:20201005T180000
DTSTAMP:20260424T030104
CREATED:20200915T060706Z
LAST-MODIFIED:20240705T194131Z
UID:2967-1601917200-1601920800@dimag.ibs.re.kr
SUMMARY:Hong Liu (刘鸿)\, Cycles and trees in graphs (1/8)
DESCRIPTION:This lecture series covers several different techniques on embedding paths/trees/cycles in (pseudo)random graphs/expanders as (induced) subgraphs.
URL:https://dimag.ibs.re.kr/event/2020-10-05/
LOCATION:Zoom ID:8628398170 (123450)
CATEGORIES:Online Lecture Series
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20201006T170000
DTEND;TZID=Asia/Seoul:20201006T180000
DTSTAMP:20260424T030104
CREATED:20200915T060857Z
LAST-MODIFIED:20240705T194130Z
UID:2969-1602003600-1602007200@dimag.ibs.re.kr
SUMMARY:Hong Liu (刘鸿)\, Cycles and trees in graphs (2/8)
DESCRIPTION:This lecture series covers several different techniques on embedding paths/trees/cycles in (pseudo)random graphs/expanders as (induced) subgraphs.
URL:https://dimag.ibs.re.kr/event/2020-10-06/
LOCATION:Zoom ID:8628398170 (123450)
CATEGORIES:Online Lecture Series
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20201007T170000
DTEND;TZID=Asia/Seoul:20201007T180000
DTSTAMP:20260424T030104
CREATED:20200915T061653Z
LAST-MODIFIED:20240705T194128Z
UID:2971-1602090000-1602093600@dimag.ibs.re.kr
SUMMARY:Hong Liu (刘鸿)\, Cycles and trees in graphs (3/8)
DESCRIPTION:This lecture series covers several different techniques on embedding paths/trees/cycles in (pseudo)random graphs/expanders as (induced) subgraphs.
URL:https://dimag.ibs.re.kr/event/2020-10-07/
LOCATION:Zoom ID:8628398170 (123450)
CATEGORIES:Online Lecture Series
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20201008T170000
DTEND;TZID=Asia/Seoul:20201008T180000
DTSTAMP:20260424T030104
CREATED:20200915T061756Z
LAST-MODIFIED:20240705T194127Z
UID:2974-1602176400-1602180000@dimag.ibs.re.kr
SUMMARY:Hong Liu (刘鸿)\, Cycles and trees in graphs (4/8)
DESCRIPTION:This lecture series covers several different techniques on embedding paths/trees/cycles in (pseudo)random graphs/expanders as (induced) subgraphs.
URL:https://dimag.ibs.re.kr/event/2020-10-08/
LOCATION:Zoom ID:8628398170 (123450)
CATEGORIES:Online Lecture Series
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20201012T170000
DTEND;TZID=Asia/Seoul:20201012T180000
DTSTAMP:20260424T030104
CREATED:20200915T061926Z
LAST-MODIFIED:20240705T194125Z
UID:2976-1602522000-1602525600@dimag.ibs.re.kr
SUMMARY:Hong Liu (刘鸿)\, Cycles and trees in graphs (5/8)
DESCRIPTION:This lecture series covers several different techniques on embedding paths/trees/cycles in (pseudo)random graphs/expanders as (induced) subgraphs.
URL:https://dimag.ibs.re.kr/event/2020-10-12/
LOCATION:Zoom ID:8628398170 (123450)
CATEGORIES:Online Lecture Series
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20201013T170000
DTEND;TZID=Asia/Seoul:20201013T180000
DTSTAMP:20260424T030104
CREATED:20200915T062032Z
LAST-MODIFIED:20240705T194124Z
UID:2978-1602608400-1602612000@dimag.ibs.re.kr
SUMMARY:Hong Liu (刘鸿)\, Cycles and trees in graphs (6/8)
DESCRIPTION:This lecture series covers several different techniques on embedding paths/trees/cycles in (pseudo)random graphs/expanders as (induced) subgraphs.
URL:https://dimag.ibs.re.kr/event/2020-10-13/
LOCATION:Zoom ID:8628398170 (123450)
CATEGORIES:Online Lecture Series
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20201014T170000
DTEND;TZID=Asia/Seoul:20201014T180000
DTSTAMP:20260424T030104
CREATED:20200915T062130Z
LAST-MODIFIED:20240705T194123Z
UID:2980-1602694800-1602698400@dimag.ibs.re.kr
SUMMARY:Hong Liu (刘鸿)\, Cycles and trees in graphs (7/8)
DESCRIPTION:This lecture series covers several different techniques on embedding paths/trees/cycles in (pseudo)random graphs/expanders as (induced) subgraphs.
URL:https://dimag.ibs.re.kr/event/2020-10-14/
LOCATION:Zoom ID:8628398170 (123450)
CATEGORIES:Online Lecture Series
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20201015T170000
DTEND;TZID=Asia/Seoul:20201015T180000
DTSTAMP:20260424T030104
CREATED:20200915T062234Z
LAST-MODIFIED:20240705T194121Z
UID:2982-1602781200-1602784800@dimag.ibs.re.kr
SUMMARY:Hong Liu (刘鸿)\, Cycles and trees in graphs (8/8)
DESCRIPTION:This lecture series covers several different techniques on embedding paths/trees/cycles in (pseudo)random graphs/expanders as (induced) subgraphs.
URL:https://dimag.ibs.re.kr/event/2020-10-15/
LOCATION:Zoom ID:8628398170 (123450)
CATEGORIES:Online Lecture Series
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20201021T163000
DTEND;TZID=Asia/Seoul:20201021T173000
DTSTAMP:20260424T030104
CREATED:20200930T112510Z
LAST-MODIFIED:20240707T082519Z
UID:3085-1603297800-1603301400@dimag.ibs.re.kr
SUMMARY:Joonkyung Lee (이준경)\, On graph norms for complex-valued functions
DESCRIPTION:For any given graph $H$\, one may define a natural corresponding functional $\|.\|_H$ for real-valued functions by using homomorphism density. One may also extend this to complex-valued functions\, once $H$ is paired with a $2$-edge-colouring $\alpha$ to assign conjugates. We say that $H$ is real-norming (resp. complex-norming) if $\|.\|_H$ (resp. there is $\alpha$ such that $\|.\|_{H\,\alpha}$) is a norm on the vector space of real-valued (resp. complex-valued) functions. This generalises Gowers norms\, a widely used tool in extremal combinatorics to quantify quasirandomness. \nWe unify these two seemingly different notions of graph norms in real- and complex-valued settings\, by proving that $H$ is complex-norming if and only if it is real-norming. Our proof does not explicitly construct a suitable $2$-edge-colouring $\alpha$ but obtain its existence and uniqueness\, which may be of independent interest. \nAs an application\, we give various example graphs that are not norming. In particular\, we show that hypercubes are not norming\, which answers the only question appeared in Hatami’s pioneering work in the area that remained untouched. This is joint work with Alexander Sidorenko.
URL:https://dimag.ibs.re.kr/event/2020-10-21/
LOCATION:Room B232\, IBS (기초과학연구원)
CATEGORIES:Discrete Math Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20201022T101000
DTEND;TZID=Asia/Seoul:20201022T111000
DTSTAMP:20260424T030104
CREATED:20200927T024614Z
LAST-MODIFIED:20240705T194022Z
UID:3056-1603361400-1603365000@dimag.ibs.re.kr
SUMMARY:Chun-Hung Liu (劉俊宏)\, Asymptotic dimension of minor-closed families and beyond
DESCRIPTION:The asymptotic dimension of metric spaces is an important notion in  geometric group theory. The metric spaces considered in this talk are  the ones whose underlying spaces are the vertex-sets of (edge-)weighted  graphs and whose metrics are the distance functions in weighted graphs.  A standard compactness argument shows that it suffices to consider the  asymptotic dimension of classes of finite weighted graphs. We prove that  the asymptotic dimension of any minor-closed family of weighted graphs\,  any class of weighted graphs of bounded tree-width\, and any class of  graphs of bounded layered tree-width are at most 2\, 1\, and 2\,  respectively. The first result solves a question of Fujiwara and  Papasoglu; the second and third results solve a number of questions of  Bonamy\, Bousquet\, Esperet\, Groenland\, Pirot and Scott. These bounds for  asymptotic dimension are optimal and generalize and improve some results  in the literature\, including results for Riemannian surfaces and Cayley  graphs of groups with a forbidden minor.
URL:https://dimag.ibs.re.kr/event/2020-10-22/
LOCATION:Zoom ID:95464969835 (356260)
CATEGORIES:Virtual Discrete Math Colloquium
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20201027T163000
DTEND;TZID=Asia/Seoul:20201027T173000
DTSTAMP:20260424T030104
CREATED:20201009T013533Z
LAST-MODIFIED:20240707T082504Z
UID:3107-1603816200-1603819800@dimag.ibs.re.kr
SUMMARY:Jeong Ok Choi (최정옥)\, Various game-theoretic models on graphs
DESCRIPTION:We introduce some of well-known game-theoretic graph models and related problems. \nA contagion game model explains how an innovation diffuses over a given network structure and focuses on finding conditions on which structure an innovation becomes epidemic. Regular infinite graphs are interesting examples to explore. We show that regular infinite trees make an innovation least advantageous to be epidemic considering the whole class of infinite regular graphs. \nA network creation game model\, on the other hand\, tries to explain the dynamics on forming a network structure when each vertex plays independently and selfishly. An important question is how costly a formation can be made without any central coordination\, and the concept of Price of Anarchy (PoA) is introduced. In the model originally suggested by Fabrikant et al.\, PoA measures how bad the forming cost can be at Nash equilibria compared to absolute minimum\, and they conjectured that this inefficiency can happen only when some tree structures are formed (Tree Conjecture). We will introduce recent progress on this tree conjecture\, remaining open problems\, and possible variations. \nThis talk includes part of joint work with Unjong Yu.
URL:https://dimag.ibs.re.kr/event/2020-10-27/
LOCATION:Room B232\, IBS (기초과학연구원)
CATEGORIES:Discrete Math Seminar
END:VEVENT
END:VCALENDAR