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X-WR-CALNAME:Center for Complex Geometry
X-ORIGINAL-URL:https://ccg.ibs.re.kr
X-WR-CALDESC:Events for Center for Complex Geometry
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BEGIN:VTIMEZONE
TZID:Asia/Seoul
BEGIN:STANDARD
TZOFFSETFROM:+0900
TZOFFSETTO:+0900
TZNAME:KST
DTSTART:20230101T000000
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END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250404T140000
DTEND;TZID=Asia/Seoul:20250404T150000
DTSTAMP:20260415T221532
CREATED:20250318T131808Z
LAST-MODIFIED:20250318T131808Z
UID:3707-1743775200-1743778800@ccg.ibs.re.kr
SUMMARY:Thibaut Delcroix\, Weighted Kähler geometry and semisimple principal fibrations (Lecture II)
DESCRIPTION:    Speaker\n\n\nThibaut Delcroix\nUniversité de Montpellier\n\n\n\n\n\n\nIn Kähler geometry\, especially in the questions of existence of canonical Kähler metrics\, the volume form ωn associated with a Kähler form ω plays a central role. In weighted Kähler geometry\, we consider a Kähler manifold X equipped with a Hamiltonian action of a torus T\, a moment map μ and associated moment polytope Δ=μ(X). We fix a weight function v:Δ → (0\,+∞)\, then replace the volume form ωn by v ◦ μ ωn. One can then define new canonical Kähler metrics: weighted solitons and weighted cscK metrics (introduced by Lahdili)\, which include most classical canonical Kähler metrics. \nI will first introduce this weighted setting\, then the (analytic) weighted delta invariant\, a number that encodes the existence of weighted solitons. I will then present a sufficient condition of existence of weighted cscK metrics\, in line with the J-flow approach of Song-Weinkove. Then I will focus on the semisimple principal fibration cosntruction\, a construction of varieties from a principal torus bundle and a fiber. The link with weighted Kähler geometry is that\, under assumptions on the principal bundle\, the Kähler geometry of the total space reduces to the weighted Kähler geometry of the fiber.
URL:https://ccg.ibs.re.kr/event/2025-0404/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250403T110000
DTEND;TZID=Asia/Seoul:20250403T120000
DTSTAMP:20260415T221532
CREATED:20250304T060837Z
LAST-MODIFIED:20250313T070340Z
UID:3664-1743678000-1743681600@ccg.ibs.re.kr
SUMMARY:Jinhyung Park\, Effective gonality theorem on weight-one syzygies of algebraic curves
DESCRIPTION:    Speaker\n\n\nJinhyung Park\nKAIST\n\n\n\n\n\n\nIn 1986\, Green-Lazarsfeld raised the gonality conjecture asserting that the gonality gon(C) of a smooth projective curve C of genus g can be read off from weight-one syzygies of a sufficiently positive line bundle L\, and also proposed possible least degree of L\, that is 2g+gon(C)-1. In 2015\, Ein-Lazarsfeld proved the conjecture when deg(L) is sufficiently large\, but the effective part of the conjecture remained widely open and was reformulated explicitly by Farkas-Kemeny a few years ago. We show an effective vanishing theorem for weight-one syzygies\, which implies that the gonality conjecture holds if deg(L) is at least 2g+gon(C) or equal to 2g+gon(C)-1 and C is not a plane curve. As Castryck observed that the gonality conjecture may not hold for a plane curve when deg(L)=2g+gon(C)-1\, this result is the best possible and thus gives a complete answer to the gonality conjecture. This is joint work with Wenbo Niu.
URL:https://ccg.ibs.re.kr/event/2025-0403/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250402T160000
DTEND;TZID=Asia/Seoul:20250402T170000
DTSTAMP:20260415T221532
CREATED:20250313T065957Z
LAST-MODIFIED:20250331T055034Z
UID:3690-1743609600-1743613200@ccg.ibs.re.kr
SUMMARY:Mihai Paun\, Hermitian-Einstein metrics for stable coherent sheaves and Bogomolov-Gieseker inequality(Lecture III)
DESCRIPTION:    Speaker\n\n\nMihai Paun\nU. Bayreuth\n\n\n\n\n\n\nI will survey the main results obtained in the articles arXiv:2501.18088 and arXiv:2405.10003. There will be no “serious” proofs\, I will nevertheless try to highlight the main ingredients in our arguments.
URL:https://ccg.ibs.re.kr/event/2025-0402/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Several Complex Variables Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250402T140000
DTEND;TZID=Asia/Seoul:20250402T150000
DTSTAMP:20260415T221532
CREATED:20250318T131130Z
LAST-MODIFIED:20250318T131609Z
UID:3702-1743602400-1743606000@ccg.ibs.re.kr
SUMMARY:Thibaut Delcroix\, Weighted Kähler geometry and semisimple principal fibrations (Lecture I)
DESCRIPTION:    Speaker\n\n\nThibaut Delcroix\nUniversité de Montpellier\n\n\n\n\n\n\nIn Kähler geometry\, especially in the questions of existence of canonical Kähler metrics\, the volume form ωn associated with a Kähler form ω plays a central role. In weighted Kähler geometry\, we consider a Kähler manifold X equipped with a Hamiltonian action of a torus T\, a moment map μ and associated moment polytope Δ=μ(X). We fix a weight function v:Δ → (0\,+∞)\, then replace the volume form ωn by v ◦ μ ωn. One can then define new canonical Kähler metrics: weighted solitons and weighted cscK metrics (introduced by Lahdili)\, which include most classical canonical Kähler metrics. \nI will first introduce this weighted setting\, then the (analytic) weighted delta invariant\, a number that encodes the existence of weighted solitons. I will then present a sufficient condition of existence of weighted cscK metrics\, in line with the J-flow approach of Song-Weinkove. Then I will focus on the semisimple principal fibration cosntruction\, a construction of varieties from a principal torus bundle and a fiber. The link with weighted Kähler geometry is that\, under assumptions on the principal bundle\, the Kähler geometry of the total space reduces to the weighted Kähler geometry of the fiber.
URL:https://ccg.ibs.re.kr/event/2025-0402-2/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250401T110000
DTEND;TZID=Asia/Seoul:20250401T120000
DTSTAMP:20260415T221532
CREATED:20250313T065849Z
LAST-MODIFIED:20250325T081601Z
UID:3686-1743505200-1743508800@ccg.ibs.re.kr
SUMMARY:Mihai Paun\, Positivity of quotients of holomorphic tensor fields (Lecture II)
DESCRIPTION:    Speaker\n\n\nMihai Paun\nU. Bayreuth\n\n\n\n\n\n\nI will present the main results and techniques in the preprint arxiv:2502.02183 (joint with J. Cao). This was motivated by the recent preprint by W. Ou\, cf. arXiv:2501.1808 (especially by the algebraicity criteria for foliations on compact Kähler manifolds in this article). \nThe first lecture is dedicated to the proof of the aforementioned algebraicity criteria. Two main techniques are coming into the picture here. One is the usual substitute for the absence of ample line bundles on compact Kähler manifolds\, i.e. the Monge-Ampère equation (combined with the mass concentration method). The second one concerns basic properties of Lelong numbers of closed positive currents. \nIn the second lecture I will survey a few results concerning the positivity of direct images\, and the finally I will explain the proof of the main results (i.e. the complete generalisation to the Kähler case of the results obtained in collaboration with F. Campana).
URL:https://ccg.ibs.re.kr/event/2025-0401/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Several Complex Variables Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250331T110000
DTEND;TZID=Asia/Seoul:20250331T120000
DTSTAMP:20260415T221532
CREATED:20250313T065542Z
LAST-MODIFIED:20250325T081534Z
UID:3684-1743418800-1743422400@ccg.ibs.re.kr
SUMMARY:Mihai Paun\, Positivity of quotients of holomorphic tensor fields (Lecture I)
DESCRIPTION:    Speaker\n\n\nMihai Paun\nU. Bayreuth\n\n\n\n\n\n\nI will present the main results and techniques in the preprint arxiv:2502.02183 (joint with J. Cao). This was motivated by the recent preprint by W. Ou\, cf. arXiv:2501.1808 (especially by the algebraicity criteria for foliations on compact Kähler manifolds in this article). \nThe first lecture is dedicated to the proof of the aforementioned algebraicity criteria. Two main techniques are coming into the picture here. One is the usual substitute for the absence of ample line bundles on compact Kähler manifolds\, i.e. the Monge-Ampère equation (combined with the mass concentration method). The second one concerns basic properties of Lelong numbers of closed positive currents. \nIn the second lecture I will survey a few results concerning the positivity of direct images\, and the finally I will explain the proof of the main results (i.e. the complete generalisation to the Kähler case of the results obtained in collaboration with F. Campana).
URL:https://ccg.ibs.re.kr/event/2025-0331/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Several Complex Variables Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250320T150000
DTEND;TZID=Asia/Seoul:20250320T163000
DTSTAMP:20260415T221532
CREATED:20250227T014235Z
LAST-MODIFIED:20250313T070308Z
UID:3645-1742482800-1742488200@ccg.ibs.re.kr
SUMMARY:Lorenzo Barban\, Geometric realization of birational maps among Mori dream spaces
DESCRIPTION:    Speaker\n\n\nLorenzo Barban\nIBS CCG\n\n\n\n\n\n\nGiven a birational map ϕ among normal projective varieties\, a geometric realization of ϕ is a normal projective C*-variety such that the birational map among geometric quotients parametrizing general orbits coincides with ϕ. Geometric realizations can be thought of as a projective algebraic version of the notion of cobordism coming from Morse theory. After recalling basic facts about Mori dream spaces\, we show that any birational map among Mori dream spaces admits a geometric realization. In the context of toric varieties\, we present a SageMath function to explicitly compute the polytope of the geometric realization. We conclude providing explicit examples of this construction.
URL:https://ccg.ibs.re.kr/event/2025-0320/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250319T150000
DTEND;TZID=Asia/Seoul:20250319T163000
DTSTAMP:20260415T221532
CREATED:20250227T014115Z
LAST-MODIFIED:20250313T070255Z
UID:3643-1742396400-1742401800@ccg.ibs.re.kr
SUMMARY:Lorenzo Barban\, Geometric Invariant Theory for C*-actions
DESCRIPTION:    Speaker\n\n\nLorenzo Barban\nIBS CCG\n\n\n\n\n\n\nIn this second talk\, which is the technical core of the lecture series\, we describe several tools to study C*-actions on projective varieties\, such as the bandwidth\, the AMvsFM Lemma\, and the pruning of a variety. With this\, we will be able to describe the -birational geometry of the- geometric quotients of a C* action on a pair (X\, L)\, with X a normal projective variety and L an ample line bundle on X. We will conclude by characterizing C*-varieties with small bandwidth.
URL:https://ccg.ibs.re.kr/event/2025-0319/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250318T150000
DTEND;TZID=Asia/Seoul:20250318T163000
DTSTAMP:20260415T221532
CREATED:20250227T013900Z
LAST-MODIFIED:20250313T070242Z
UID:3641-1742310000-1742315400@ccg.ibs.re.kr
SUMMARY:Lorenzo Barban\, General results on C*-actions on projective varieties
DESCRIPTION:    Speaker\n\n\nLorenzo Barban\nIBS CCG\n\n\n\n\n\n\nIn this lecture series we aim to describe the rich relation between C*-actions on complex normal projetive varieties and the birational maps among the associated geometric quotients. We will begin this first seminar by explaining a motivating example\, called the Atiyah flop. We will then discuss general results on normal projective varieties admitting a C*-action\, such as Sumihiro’s theorem and Białynicki-Birula theorem. We will then conclude by describing how much a C*-action affects the birational geometry of a C*-variety.
URL:https://ccg.ibs.re.kr/event/2025-0318/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250310
DTEND;VALUE=DATE:20250314
DTSTAMP:20260415T221532
CREATED:20241028T081418Z
LAST-MODIFIED:20250311T114104Z
UID:3471-1741564800-1741910399@ccg.ibs.re.kr
SUMMARY:Workshop on Hyperkähler Varieties and Related Topics
DESCRIPTION:Invited Speakers (three one-hour lectures)\nEkaterina Amerik (HSE U.)\nYoonjoo Kim (Columbia U.)\nZhiyuan Li (SCMS\, Fudan U.)\nKeiji Oguiso (U. Tokyo) \nAbstracts\nPDF file \nSchedule\nMarch 10 (Monday) \n14:00-15:00 Registration\n15:00-16:00 Amerik\, Lecture I\n16:00-16:30 Coffee Break\n16:30-17:30 Li\, Lecture I\n18:00-20:00 Speakers dinner \nMarch 11 (Tuesday) \n11:00-12:00 Amerik\, Lecture II\n12:00-14:00 Lunch\n14:00-15:00 Li\, Lecture II\n15:00-15:20 Coffee Break\n15:20-16:20 Kim\, Lecture I\n16:20-16:40 Coffee Break\n16:40-17:40 Oguiso\, Lecture I\n18:00-20:00 Banquet \nMarch 12 (Wednesday) \n11:00-12:00 Kim\, Lecture II\n12:00-14:00 Lunch\n14:00-15:00 Oguiso\, Lecture II\n15:00-15:20 Coffee Break\n15:20-16:20 Amerik\, Lecture III\n16:20-16:40 Coffee Break\n16:40-17:40 Li\, Lecture III\n18:00-20:00 Speakers dinner \nMarch 13 (Thursday) \n11:00-12:00 Kim\, Lecture III\n12:00-14:00 Lunch\n14:00-15:00 Oguiso\, Lecture III \nOrganizers\nJun-Muk Hwang (IBS-CCG)\nYongnam Lee (IBS-CCG / KAIST) \nVenue\nB109\, IBS\, Daejeon\, Korea \nRegistration\nPlease submit Google form from February 3 to 23. \nMore Information\n• How to get to IBS-CCG
URL:https://ccg.ibs.re.kr/event/2025-0310-0313/
LOCATION:B109\, IBS\, Korea\, Republic of
CATEGORIES:Conferences and Workshops
ATTACH;FMTTYPE=image/jpeg:https://ccg.ibs.re.kr/wp-content/uploads/2025/03/Workshop-on-Hyperk_hler-Varieties-and-Related-Topics-scaled.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250227T170000
DTEND;TZID=Asia/Seoul:20250227T180000
DTSTAMP:20260415T221532
CREATED:20250218T001512Z
LAST-MODIFIED:20250218T001559Z
UID:3624-1740675600-1740679200@ccg.ibs.re.kr
SUMMARY:Ngoc Cuong Nguyen\, Equidistribution of Fekete points on projective manifolds
DESCRIPTION:    Speaker\n\n\nNgoc Cuong Nguyen\nKAIST\n\n\n\n\n\n\nWe survey recent developments on the speed of convergence of Fekete points on projective manifolds where the equidistribution was proved by Berman and Boucksom (2011). In particular\, the convergence speed can be obtained for a large class of polynomially cuspidal compact sets introduced by Pawłucki and Pleśniak (1988). These sets are (Cα\, Cα’)-regular in the sense of Dinh\, Ma and Nguyen (2017).
URL:https://ccg.ibs.re.kr/event/2025-0227-2/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250227T150000
DTEND;TZID=Asia/Seoul:20250227T163000
DTSTAMP:20260415T221532
CREATED:20250205T121541Z
LAST-MODIFIED:20250205T121541Z
UID:3600-1740668400-1740673800@ccg.ibs.re.kr
SUMMARY:Sung-Yeon Kim\, Proper holomorphic maps between bounded symmetric domains
DESCRIPTION:    Speaker\n\n\nSung-Yeon Kim\nIBS CCG\n\n\n\n\n\n\nIn this talk\, we study the rigidity of proper holomorphic maps f: Ω→Ω‘​​ between irreducible bounded symmetric domains Ω​​ and Ω‘​​. First\, we will define the moduli maps induced by f​​. This moduli maps are CR maps between real orbits in flag maniflods. If the rank difference is small\, i.e.\, 2 ≤ rank(Ω‘)< 2 rank(Ω)-1​​\, then there exists a moduli map which preserves the VMRT structures on the real orbits. Using this property\, we will show that f: Ω → Ω‘​​ is a holomorphic totally geodesic isometric embedding with respect to Kobayashi metrics for certain pairs (Ω\, Ω‘)​​. This is a joint work with N. Mok and A. Seo.
URL:https://ccg.ibs.re.kr/event/2025-0227/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250226T150000
DTEND;TZID=Asia/Seoul:20250226T163000
DTSTAMP:20260415T221532
CREATED:20250205T121238Z
LAST-MODIFIED:20250205T121730Z
UID:3598-1740582000-1740587400@ccg.ibs.re.kr
SUMMARY:Sung-Yeon Kim\, Real orbits in flag manifolds
DESCRIPTION:    Speaker\n\n\nSung-Yeon Kim\nIBS CCG\n\n\n\n\n\n\nLet G​ be a complex semisimple Lie group\, P​​ be a parabolic subgroup and G0​​ be a real form of G.​​ Then the flag manifold G/P​​ decomposes into finitely many G0-orbits. The complex structure of G/P​​ yields a natural homogeneous CR manifold structure on the real orbits such that all elements in G0 are CR automorphisms. Among them there is exactly one orbit of minimal dimension\, which is compact. Shilov boundary of bounded symmetric domains are the well-known examples of such minimal orbits. In this talk\, we study real orbits from the point of view of CR geometry. In particular we study the CR structures on the minimal orbits in Grassmannians.
URL:https://ccg.ibs.re.kr/event/2025-0226/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250210
DTEND;VALUE=DATE:20250215
DTSTAMP:20260415T221532
CREATED:20241101T094651Z
LAST-MODIFIED:20241112T041005Z
UID:3490-1739145600-1739577599@ccg.ibs.re.kr
SUMMARY:Combinatorics on flag varieties and related topics 2025
DESCRIPTION:Speakers\nTatsuyuki Hikita (RIMS)\nByung-Hak Hwang (KIAS)\nTakeshi Ikeda (Waseda University)\nMinyoung Jeon (University of Georgia)\nDonggun Lee (IBS-CCG)\nEunjeong Lee (Chungbuk National University)\nSeung Jin Lee (Seoul National University)\nMikiya Masuda (OCAMI)\nSeonjeong Park (Jeonju University)\nMartha Precup (Washington University in St. Louis)\nMark Skandera (Lehigh University)\nJohn Shareshian (Washington University in St. Louis)\nFoster Tom (Massachusetts Institute of Technology) \nOrganizers\nSoojin Cho (Ajou University)\nYunhyung Cho (Sungkyunkwan University)\nJaehyun Hong (IBS-CCG)\nJiSun Huh (Ajou University)\nEunjeong Lee (Chungbuk National University)\nSeonjeong Park (Jeonju University) \nVenue\nAjou University\, Suwon\, Republic of Korea \nRegistration\nPlease submit Google form by January 10th\, 2025. \nFor details\, see https://sites.google.com/view/flagvarieties2025/home.
URL:https://ccg.ibs.re.kr/event/2025-0210-0214/
LOCATION:Ajou University\, Suwon\, Korea\, Republic of
CATEGORIES:Conferences and Workshops
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250122T160000
DTEND;TZID=Asia/Seoul:20250122T170000
DTSTAMP:20260415T221532
CREATED:20250114T162100Z
LAST-MODIFIED:20250114T162100Z
UID:3571-1737561600-1737565200@ccg.ibs.re.kr
SUMMARY:Shuang Su\, Volumes of Components of Lelong Upper Level Sets
DESCRIPTION:    Speaker\n\n\nShuang Su\nUniversity of Cologne\n\n\n\n\n\n\nIn this talk\, I will talk about the joint work with Duc-Viet Vu. We establish an optimal upper bound for the volumes of components of Lelong upper level sets of closed positive (1\,1)-currents\, in terms of non-pluripolar products of currents.
URL:https://ccg.ibs.re.kr/event/2025-0122/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Several Complex Variables Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250109T150000
DTEND;TZID=Asia/Seoul:20250109T163000
DTSTAMP:20260415T221532
CREATED:20241204T055643Z
LAST-MODIFIED:20241204T060156Z
UID:3529-1736434800-1736440200@ccg.ibs.re.kr
SUMMARY:Sung Wook Jang\, Potential Log Discrepancy and Minimal Model Program III
DESCRIPTION:    Speaker\n\n\nSung Wook Jang\nIBS CCG\n\n\n\n\n\n\nWe can run an MMP for an lc pair. However\, in general\, we do not know whether the MMP terminates or not. Nevertheless\, we can show that special MMP terminates. Immediately\, we can prove the existence of minimal models for certain pairs. Analogously\, for an anticanonical divisor\, if we impose appropriate conditions\, then we can say that there exists an anticanonical minimal model. Furthermore\, we will talk about ongoing project on anticanonical minimal model program.
URL:https://ccg.ibs.re.kr/event/2025-0109/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250108T150000
DTEND;TZID=Asia/Seoul:20250108T163000
DTSTAMP:20260415T221532
CREATED:20241204T055455Z
LAST-MODIFIED:20241204T060110Z
UID:3527-1736348400-1736353800@ccg.ibs.re.kr
SUMMARY:Sung Wook Jang\, Potential Log Discrepancy and Minimal Model Program II
DESCRIPTION:    Speaker\n\n\nSung Wook Jang\nIBS CCG\n\n\n\n\n\n\nWe are interested in an anticanonical divisor and hope to establish the MMP for an anticanonical divisor. We believe that the beginning point is the potential log discrepancy that controls singularities of a possible resulting model of MMP for an anticanonical divisor. In this talk\, we will give the definition and properties of the potential log discrepancy. We can also define a plc threshold in terms of the potential log discrepancy and show that plc thresholds satisfy ACC.
URL:https://ccg.ibs.re.kr/event/2025-0108/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250107T150000
DTEND;TZID=Asia/Seoul:20250107T163000
DTSTAMP:20260415T221532
CREATED:20241204T055300Z
LAST-MODIFIED:20241204T060005Z
UID:3525-1736262000-1736267400@ccg.ibs.re.kr
SUMMARY:Sung Wook Jang\, Potential Log Discrepancy and Minimal Model Program I
DESCRIPTION:    Speaker\n\n\nSung Wook Jang\nIBS CCG\n\n\n\n\n\n\nMinimal model program (abbreviated as MMP) is a central problem in birational geometry. The MMP is a sequence of divisorial contractions or flips\, which makes the canonical divisor closer to a nef divisor. If the MMP successfully terminates\, then we have either a minimal model or a Mori fiber space. We will briefly show how to run an MMP and introduce recent progress concerned with the MMP.
URL:https://ccg.ibs.re.kr/event/2025-0107/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20241230T113000
DTEND;TZID=Asia/Seoul:20241230T122000
DTSTAMP:20260415T221532
CREATED:20241211T050722Z
LAST-MODIFIED:20241217T042547Z
UID:3543-1735558200-1735561200@ccg.ibs.re.kr
SUMMARY:Yonghwa Cho\, Double Point Divisors from Projections
DESCRIPTION:    Speaker\n\n\nYonghwa Cho\nGyeongsang National University\n\n\n\n\n\n\nConsider a smooth projective variety of codimension e. A general projection from a linear subspace of dimension (e-2) is birational\, hence the non-isomorphic locus forms a proper closed subset of X. Mumford showed that this non-isomorphic locus is not merely a closed subset\, but is naturally endowed with a divisor structure. We call it a double point divisor from outer projection. In this talk I will discuss the positivity property of double point divisors including our recent proof of very ampleness\, except for some exceptional cases. This work is based on a joint work with Jinhyung Park.
URL:https://ccg.ibs.re.kr/event/2024-1230-1130-1220/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20241230T103000
DTEND;TZID=Asia/Seoul:20241230T112000
DTSTAMP:20260415T221532
CREATED:20241211T050548Z
LAST-MODIFIED:20241220T005212Z
UID:3541-1735554600-1735557600@ccg.ibs.re.kr
SUMMARY:Sungmin Yoo\, Convergence of Sequences of the Bergman Type Volume Forms
DESCRIPTION:    Speaker\n\n\nSungmin Yoo\nIncheon National University\n\n\n\n\n\n\nFollowing the Yau-Tian-Donaldson conjecture\, the construction of sequences of Bergman-type metrics converging to a canonical metric on a polarized manifold has been studied by many mathematicians including Tian\, Donaldson\, Tsuji\, Berman\, Berndtsson\, and others. In this talk\, I will introduce my recent findings on the uniform convergence of Tsuji’s Bergman kernel sequence to the volume form of the Kahler-Einstein metric on a uniformly squeezing domain.
URL:https://ccg.ibs.re.kr/event/2024-1230-1030-1120/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20241211T160000
DTEND;TZID=Asia/Seoul:20241211T170000
DTSTAMP:20260415T221532
CREATED:20241118T134009Z
LAST-MODIFIED:20241118T134128Z
UID:3512-1733932800-1733936400@ccg.ibs.re.kr
SUMMARY:Luca Schaffler\, Unimodal Singularities and Boundary Divisors in the KSBA Moduli of a Class of Horikawa Surfaces
DESCRIPTION:    Speaker\n\n\nLuca Schaffler\nRoma Tre University\n\n\n\n\n\n\nSmooth minimal surfaces of general type with K2=1\, pg=2\, and q=0 constitute a fundamental example in the geography of algebraic surfaces\, and the 28-dimensional moduli space M of their canonical models admits a modular compactification M via the minimal model program. We describe eight new irreducible boundary divisors in such compactification parametrizing reducible stable surfaces. Additionally\, we study the relation with the GIT compactification of M and the Hodge theory of the degenerate surfaces that the eight divisors parametrize. Time permitting\, we will discuss recent progress aimed at generalizing these techniques to study the boundary of compact moduli of other types of stable surfaces. This is joint work with Patricio Gallardo\, Gregory Pearlstein\, and Zheng Zhang.
URL:https://ccg.ibs.re.kr/event/2024-1211/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20241211T110000
DTEND;TZID=Asia/Seoul:20241211T120000
DTSTAMP:20260415T221532
CREATED:20241119T054930Z
LAST-MODIFIED:20241119T054930Z
UID:3515-1733914800-1733918400@ccg.ibs.re.kr
SUMMARY:Yen-An Chen\, Toric Fano Foliations
DESCRIPTION:    Speaker\n\n\nYen-An Chen\nNational Taiwan University\n\n\n\n\n\n\nIn recent years\, there are significant developments of the minimal model program for foliated varieties. It is intriguing to ask if Fano foliations form a bounded family. It is anticipated that Borisov-Alexeev-Borisov conjecture also holds in the context of foliations. In this talk\, I will discuss the boundedness of the toric Fano adjoint foliated structure with mild singularities. This is a joint work in progress with Chih-Wei Chang.
URL:https://ccg.ibs.re.kr/event/2024-12-11/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20241206T160000
DTEND;TZID=Asia/Seoul:20241206T170000
DTSTAMP:20260415T221532
CREATED:20241118T133626Z
LAST-MODIFIED:20241118T133626Z
UID:3509-1733500800-1733504400@ccg.ibs.re.kr
SUMMARY:Luca Schaffler\, An Explicit Wall Crossing for the Moduli Space of Hyperplane Arrangements
DESCRIPTION:    Speaker\n\n\nLuca Schaffler\nRoma Tre University\n\n\n\n\n\n\nThe moduli space of hyperplanes in projective space has a family of geometric and modular compactifications that parametrize stable hyperplane arrangements with respect to a weight vector. Among these\, there is a toric compactification that generalizes the Losev-Manin moduli space of points on the line. We study the first natural wall crossing that modifies this compactification into a non-toric one by varying the weights. As an application of our work\, we show that any Q-factorialization of the blow up at the identity of the torus of the generalized Losev-Manin space is not a Mori dream space for a sufficiently high number of hyperplanes. Additionally\, for lines in the plane\, we provide a precise description of the wall crossing. This is joint work with Patricio Gallardo.
URL:https://ccg.ibs.re.kr/event/2024-1206/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20241128T110000
DTEND;TZID=Asia/Seoul:20241128T120000
DTSTAMP:20260415T221532
CREATED:20241029T022542Z
LAST-MODIFIED:20241029T022542Z
UID:3487-1732791600-1732795200@ccg.ibs.re.kr
SUMMARY:Izzet Coskun\, The Higher Rank Brill-Noether Problem on Surfaces
DESCRIPTION:    Speaker\n\n\nIzzet Coskun\nUniversity of Illinois Chicago\n\n\n\n\n\n\nIn this talk\, I will explain how to use Bridgeland stability conditions to compute the cohomology of a general stable sheaf on a K3 or abelian surface. This talk is based on joint work with Howard Nuer and Kota Yoshioka.
URL:https://ccg.ibs.re.kr/event/2024-1128/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20241127T160000
DTEND;TZID=Asia/Seoul:20241127T170000
DTSTAMP:20260415T221532
CREATED:20241029T022418Z
LAST-MODIFIED:20241029T022418Z
UID:3485-1732723200-1732726800@ccg.ibs.re.kr
SUMMARY:Izzet Coskun\, The Geometry of Moduli Spaces of Sheaves on P2
DESCRIPTION:    Speaker\n\n\nIzzet Coskun\nUniversity of Illinois Chicago\n\n\n\n\n\n\nIn this talk\, I will explain how to use Bridgeland stability conditions to compute the ample and effective cones of moduli spaces of sheaves on the projective plane. I will describe the birational geometry of these moduli spaces and give applications to the higher rank interpolation problem. This talk is based on joint work with Jack Huizenga\, John Kopper and Matthew Woolf.
URL:https://ccg.ibs.re.kr/event/2024-1127/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20241112T160000
DTEND;TZID=Asia/Seoul:20241112T170000
DTSTAMP:20260415T221532
CREATED:20240930T082034Z
LAST-MODIFIED:20241111T063450Z
UID:3357-1731427200-1731430800@ccg.ibs.re.kr
SUMMARY:Giancarlo Urzua\, The Birational Geometry of Markov Numbers
DESCRIPTION:    Speaker\n\n\nGiancarlo Urzua\nPontificia Universidad Catolica de Chile\n\n\n\n\n\n\nThe projective plane is rigid. However\, it may degenerate to surfaces with quotient singularities. After the work of Bădescu and Manetti\, Hacking and Prokhorov 2010 classified these degenerations completely. They are Q-Gorenstein partial smoothings of P(a2\, b2\, c2)\, where a\, b\, c satisfy the Markov equation x2+y2+z2=3xyz. Let us call the corresponding degenerations Markovian planes. They are part of a bigger picture of degenerations with Wahl singularities\, where there is an explicit MMP whose final results are either K nef\, smooth deformations of ruled surfaces\, or Markovian planes. Although it is a final result of MMP\, we can nevertheless run MMP on small modifications of Markovian planes to obtain new numerical/combinatorial data for Markov numbers via birational geometry. New connections with Markov conjecture (i.e. Frobenius Uniqueness Conjecture) are byproducts. This is joint work with Juan Pablo Zúñiga (Ph.D. student at UC Chile)\, the pre-print can be found here https://arxiv.org/abs/2310.17957.
URL:https://ccg.ibs.re.kr/event/2024-1112/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20241108
DTEND;VALUE=DATE:20241114
DTSTAMP:20260415T221532
CREATED:20240930T083348Z
LAST-MODIFIED:20240930T084043Z
UID:3366-1731024000-1731542399@ccg.ibs.re.kr
SUMMARY:Giancarlo Urzua (Pontificia Universidad Catolica de Chile)
DESCRIPTION:Giancarlo Urzua \nVisitor (2024.11.8-2024.11.13) from Pontificia Universidad Catolica de Chile \nOffice: –
URL:https://ccg.ibs.re.kr/event/giancarlo-urzua-241108-241113/
CATEGORIES:Visitors
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20241029T160000
DTEND;TZID=Asia/Seoul:20241029T170000
DTSTAMP:20260415T221532
CREATED:20240930T081825Z
LAST-MODIFIED:20241014T060435Z
UID:3353-1730217600-1730221200@ccg.ibs.re.kr
SUMMARY:Naoto Yotsutani\, Bott Manifolds with the Strong Calabi Dream Structure
DESCRIPTION:    Speaker\n\n\nNaoto Yotsutani\nKagawa university\n\n\n\n\n\n\nWe prove that if the Futaki invariant of a polarized Bott manifold (X\, L) for any ample line bundle L vanishes\, then X is isomorphic to the products of the projective lines. This talk is based on a work joint with Kento Fujita (algebro-geometrical approach)\, and another independent work joint with Hajime Ono and Yuji Sano (convex geometrical approach).
URL:https://ccg.ibs.re.kr/event/2024-1029/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20241026
DTEND;VALUE=DATE:20241030
DTSTAMP:20260415T221532
CREATED:20240930T083008Z
LAST-MODIFIED:20241014T060511Z
UID:3364-1729900800-1730246399@ccg.ibs.re.kr
SUMMARY:Naoto Yotsutani (Kagawa University)
DESCRIPTION:Naoto Yotsutani \nVisitor (2024.10.26-2024.10.29) from Kagawa University \nOffice: –
URL:https://ccg.ibs.re.kr/event/naoto-yotsutani-241026-241029/
CATEGORIES:Visitors
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20241022T160000
DTEND;TZID=Asia/Seoul:20241022T170000
DTSTAMP:20260415T221532
CREATED:20241017T051012Z
LAST-MODIFIED:20241017T051012Z
UID:3397-1729612800-1729616400@ccg.ibs.re.kr
SUMMARY:David Sykes\, CR Hypersurfaces\, Studying 2-nondegenerate Structures via Absolute Parallelisms
DESCRIPTION:    Speaker\n\n\nDavid Sykes\nIBS CCG\n\n\n\n\n\n\nThe basic problem of finding (local) biholomorphisms mapping one real hypersurface in a complex space onto another is only well understood for a limited class of hypersurfaces\, and has a fundamental relationship to their induced CR geometries. Following a light historical survey of major results in the area\, this talk will present a solution to the local equivalence problem for 2-nondegenerate CR hypersurfaces\, developed in joint work with Igor Zelenko\, given by canonically encoding the geometries into absolute parallelisms.
URL:https://ccg.ibs.re.kr/event/2024-1022/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Several Complex Variables Seminar
END:VEVENT
END:VCALENDAR