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X-WR-CALDESC:Events for Center for Complex Geometry
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TZID:Asia/Seoul
BEGIN:STANDARD
TZOFFSETFROM:+0900
TZOFFSETTO:+0900
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DTSTART:20240101T000000
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BEGIN:VEVENT
DTSTART;VALUE=DATE:20250210
DTEND;VALUE=DATE:20250215
DTSTAMP:20260416T012412
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:20250226T150000
DTEND;TZID=Asia/Seoul:20250226T163000
DTSTAMP:20260416T012412
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;TZID=Asia/Seoul:20250227T150000
DTEND;TZID=Asia/Seoul:20250227T163000
DTSTAMP:20260416T012412
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:20250227T170000
DTEND;TZID=Asia/Seoul:20250227T180000
DTSTAMP:20260416T012412
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;VALUE=DATE:20250301
DTEND;VALUE=DATE:20260216
DTSTAMP:20260416T012412
CREATED:20250304T080834Z
LAST-MODIFIED:20250304T081528Z
UID:3669-1740787200-1771199999@ccg.ibs.re.kr
SUMMARY:Ngoc Cuong Nguyen (KAIST)
DESCRIPTION:Ngoc Cuong Nguyen\nVisitor (2025.3.1-2026.2.15) from KAIST\nOffice: B248
URL:https://ccg.ibs.re.kr/event/250301-260215/
CATEGORIES:Visitors
ATTACH;FMTTYPE=image/jpeg:https://ccg.ibs.re.kr/wp-content/uploads/2025/03/ncnguyen_rescaled-1.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250310
DTEND;VALUE=DATE:20250314
DTSTAMP:20260416T012412
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:20250318T150000
DTEND;TZID=Asia/Seoul:20250318T163000
DTSTAMP:20260416T012412
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;TZID=Asia/Seoul:20250319T150000
DTEND;TZID=Asia/Seoul:20250319T163000
DTSTAMP:20260416T012412
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:20250320T150000
DTEND;TZID=Asia/Seoul:20250320T163000
DTSTAMP:20260416T012412
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;VALUE=DATE:20250326
DTEND;VALUE=DATE:20250503
DTSTAMP:20260416T012412
CREATED:20250402T020950Z
LAST-MODIFIED:20250402T020950Z
UID:3736-1742947200-1746230399@ccg.ibs.re.kr
SUMMARY:Mihai Paun (Universität Bayreuth)
DESCRIPTION:Mihai Paun\nVisitor (2025.3.26-2025.5.2) from Universität Bayreuth\nOffice: B249
URL:https://ccg.ibs.re.kr/event/250326-250502/
CATEGORIES:Visitors
ATTACH;FMTTYPE=image/jpeg:https://ccg.ibs.re.kr/wp-content/uploads/2022/09/mpaun-1-e1743559781998.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250331T110000
DTEND;TZID=Asia/Seoul:20250331T120000
DTSTAMP:20260416T012412
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:20250401T110000
DTEND;TZID=Asia/Seoul:20250401T120000
DTSTAMP:20260416T012412
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:20250402T140000
DTEND;TZID=Asia/Seoul:20250402T150000
DTSTAMP:20260416T012412
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:20250402T160000
DTEND;TZID=Asia/Seoul:20250402T170000
DTSTAMP:20260416T012412
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:20250403T110000
DTEND;TZID=Asia/Seoul:20250403T120000
DTSTAMP:20260416T012412
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:20250404T140000
DTEND;TZID=Asia/Seoul:20250404T150000
DTSTAMP:20260416T012412
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:20250407T140000
DTEND;TZID=Asia/Seoul:20250407T150000
DTSTAMP:20260416T012412
CREATED:20250318T131936Z
LAST-MODIFIED:20250318T131936Z
UID:3709-1744034400-1744038000@ccg.ibs.re.kr
SUMMARY:Thibaut Delcroix\, Weighted Kähler geometry and semisimple principal fibrations (Lecture III)
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/2025-0407/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250409T140000
DTEND;TZID=Asia/Seoul:20250409T150000
DTSTAMP:20260416T012412
CREATED:20250318T132054Z
LAST-MODIFIED:20250318T132212Z
UID:3711-1744207200-1744210800@ccg.ibs.re.kr
SUMMARY:Thibaut Delcroix\, Weighted Kähler geometry and semisimple principal fibrations (Lecture IV)
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/2025-0409/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250416T160000
DTEND;TZID=Asia/Seoul:20250416T170000
DTSTAMP:20260416T012412
CREATED:20250410T074749Z
LAST-MODIFIED:20250410T074749Z
UID:3759-1744819200-1744822800@ccg.ibs.re.kr
SUMMARY:Long Li\, Plurisubharmonic functions and Sasaki geometry
DESCRIPTION:    Speaker\n\n\nLong Li\nShanghaiTech University\n\n\n\n\n\n\nIn this talk\, we will discuss the recent progress on the zero mass conjecture for plurisubharmoinc functions\, raised by Guedj and Rashkovskii. For a local plurisubharmonic function with an isolated singularity at the origin\, the conjecture states that the zero Lelong number (at the singularity) implies the zero residual Monge-Ampere mass at the same point. We confirm this conjecture under the circular symmetry condition\, with the aid from Sasaki geometry. Furthermore\, we will also apply our technique to more general plurisubharmonic functions in certain cases.
URL:https://ccg.ibs.re.kr/event/2025-0416/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Several Complex Variables Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250418T110000
DTEND;TZID=Asia/Seoul:20250418T120000
DTSTAMP:20260416T012412
CREATED:20250314T060803Z
LAST-MODIFIED:20250413T225322Z
UID:3698-1744974000-1744977600@ccg.ibs.re.kr
SUMMARY:Jie Liu\, Symplectic singularities arising from cotangent bundles
DESCRIPTION:    Speaker\n\n\nJie Liu\nAMSS\n\n\n\n\n\n\nI’ll report joint works with Baohua Fu (AMSS)\, in which we investigate symplectic singularities arising from the affinization of the cotangent bundle of a smooth variety.
URL:https://ccg.ibs.re.kr/event/2025-0418/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250421
DTEND;VALUE=DATE:20250425
DTSTAMP:20260416T012412
CREATED:20241022T235228Z
LAST-MODIFIED:20250429T025235Z
UID:3456-1745193600-1745539199@ccg.ibs.re.kr
SUMMARY:Progress in Complex Geometry
DESCRIPTION:The goal of the workshop is to INTRODUCE some of the most interesting recent developments in complex geometry to (young) people working in areas related to complex geometry. For this purpose\, the speakers will try to make the talks understandable to broad audience. \nInvited Speakers\n2-hours lectures \nBin Guo (Rutgers U.)\nShigeharu Takayama (U. Tokyo)\nDavid Witt Nyström (Chalmers U.) \n1-hour talks \nDamian Brotbek (U. Lorraine)\nYoung-Jun Choi (Pusan National U.)\nJie Liu (AMSS\, CAS)\nShinichi Matsumura (Tohoku U.)\nDror Varolin (Stony Brook U.)\nJuanyong Wang (AMSS\, CAS)\nMing Xiao (U.C. San Diego)\nJunyi Xie (Peking U.) \nAbstracts\nPDF file \nSchedule\nMonday (21st) \nChair: Jun-Muk Hwang\n10:00-11:00 Witt Nyström\n11:30-12:30 Witt Nyström \nChair: Yongnam Lee\n15:00-16:00 Liu\n16:30-17:30 Matsumura \nTuesday (22nd) \nChair: Ngoc Cuong Nguyen\n10:00-11:00 Guo\n11:30-12:30 Guo \nChair: Sungyeon Kim\n15:00-16:00 Xie\n16:30-17:30 Xiao\n18:00-20:00 Banquet \nWednesday (23rd) \nChair: DongSeon Hwang\n10:00-11:00 Takayama\n11:30-12:30 Takayama \nChair: Thibaut Delcroix\n15:00-16:00 Choi\n16:30-17:30 Wang \nThursday (24th) \nChair: Mihai Paun\n10:00-11:00 Brotbek\n11:30-12:30 Varolin \nOrganizers\nJun-Muk Hwang (IBS CCG)\nMihai Paun (Bayreuth) \nVenue\nB109\, IBS\, Daejeon\, Korea \nRegistration\nPlease submit Google form by April 6. \nMore Information\n• How to get to IBS-CCG
URL:https://ccg.ibs.re.kr/event/2025-0421-0424/
LOCATION:B109\, IBS\, Korea\, Republic of
CATEGORIES:Conferences and Workshops
ATTACH;FMTTYPE=image/jpeg:https://ccg.ibs.re.kr/wp-content/uploads/2025/04/2025_Apr_Group-photo-wide_300-scaled.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250507T160000
DTEND;TZID=Asia/Seoul:20250507T170000
DTSTAMP:20260416T012412
CREATED:20250429T025718Z
LAST-MODIFIED:20250502T110417Z
UID:3796-1746633600-1746637200@ccg.ibs.re.kr
SUMMARY:Ilya Kossovskiy\, Divergence in CR Geometry
DESCRIPTION:    Speaker\n\n\nIlya Kossovskiy\nSUSTech\n\n\n\n\n\n\nIn this lecture\, I will outline convergence and divergence phenomena for mappings of CR submanifolds in complex space. Possible applications for mappings of more general geometric structures will be also concerned.
URL:https://ccg.ibs.re.kr/event/2025-0507/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Several Complex Variables Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250508T163000
DTEND;TZID=Asia/Seoul:20250508T173000
DTSTAMP:20260416T012412
CREATED:20250404T011656Z
LAST-MODIFIED:20250404T011656Z
UID:3746-1746721800-1746725400@ccg.ibs.re.kr
SUMMARY:Meng Chen\, The Noether inequality for algebraic threefolds
DESCRIPTION:    Speaker\n\n\nMeng Chen\nFudan University\n\n\n\n\n\n\nIn this talk\, I will present a complete proof for the following theorem: the inequality K3  ≥ 4/3 pg-10/3 holds for all 3-folds of general type.
URL:https://ccg.ibs.re.kr/event/2025-0508/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250514T110000
DTEND;TZID=Asia/Seoul:20250514T120000
DTSTAMP:20260416T012412
CREATED:20250404T011824Z
LAST-MODIFIED:20250404T011824Z
UID:3748-1747220400-1747224000@ccg.ibs.re.kr
SUMMARY:Meng Chen\, On the classification of some 3-folds with small positive canonical volumes
DESCRIPTION:    Speaker\n\n\nMeng Chen\nFudan University\n\n\n\n\n\n\nIn this lecture\, I will report some new progress in studying moduli spaces of algebraic 3-folds with very small canonical volume.
URL:https://ccg.ibs.re.kr/event/2025-0514/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250519T110000
DTEND;TZID=Asia/Seoul:20250519T120000
DTSTAMP:20260416T012412
CREATED:20250508T092009Z
LAST-MODIFIED:20250508T092009Z
UID:3807-1747652400-1747656000@ccg.ibs.re.kr
SUMMARY:JongHae Keum\, Fake quadric surfaces
DESCRIPTION:    Speaker\n\n\nJongHae Keum\nKIAS\n\n\n\n\n\n\nA smooth projective complex surface S is called a Q-homology quadric if it has the same Betti numbers as the smooth quadric surface. Let S be a Q-homology quadric. Then its cohomology lattice is of rank 2\, (even or odd) unimodular. By the classification of surfaces\, S is either rational or of general type. In the latter case\, S is called a fake Q-homology quadric (fake quadric\, in short). There is an unsolved question raised by Hirzebruch: does there exist a surface of general type which is homeomorphic to the smooth quadric surface? I will report recent progress on these surfaces.
URL:https://ccg.ibs.re.kr/event/2025-0519/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250520T110000
DTEND;TZID=Asia/Seoul:20250520T120000
DTSTAMP:20260416T012412
CREATED:20250425T013616Z
LAST-MODIFIED:20250425T013616Z
UID:3784-1747738800-1747742400@ccg.ibs.re.kr
SUMMARY:Gian Pietro Pirola\, Asymptotic directions on the moduli space of curves
DESCRIPTION:    Speaker\n\n\nGian Pietro Pirola\nUniversity of Pavia\n\n\n\n\n\n\nWe present some computational improvements that allow us to study asymptotic lines in the tangent of the moduli space Mg of the curves of genus g. The asymptotic directions are those tangent directions that are annihilated by the second fundamental form induced by the Torelli map. We give examples of asymptotic lines for any g > 3 and we study their rank. The rank r(v) of a tangent direction at Mg is defined to be the rank of the cup product map associated to the infinitesimal deformation map\, that is the infinitesimal variation of Hodge structure in that direction. We show that if v is not zero and r(v)< (cliff(C) + 1) where cliff(C) is the Clifford index of C\, then v is not asymptotic and we study the case when r(v)= cliff(C). Finally all asymptotic directions of rank 1 are determined and a description of the rank 2 case is given. It is a joint work with Elisabetta Colombo and Paola Frediani.
URL:https://ccg.ibs.re.kr/event/2025-0520-2/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250520T160000
DTEND;TZID=Asia/Seoul:20250520T173000
DTSTAMP:20260416T012412
CREATED:20250415T070256Z
LAST-MODIFIED:20250513T025401Z
UID:3764-1747756800-1747762200@ccg.ibs.re.kr
SUMMARY:Benjamin McMillan\, Secondary Characteristic classes and Chern-Weil theory of (Haefliger) singular foliations I
DESCRIPTION:    Speaker\n\n\nBenjamin McMillan\nIBS CCG\n\n\n\n\n\n\nFoliations have a theory of characteristic classes that is much like that of vector bundles\, but with notable differences. Some of the characteristic classes of a foliation come from its induced normal bundle\, but there are additional secondary classes that depend on more detailed information about the foliation. Just as with vector bundles\, one can obtain the characteristic classes using either a universal space or the Chern-Weil construction (in case the foliation is regular). \nIn these talks I will explain the general theory\, and how the Chern-Weil construction can often be made to work even for singular foliations.
URL:https://ccg.ibs.re.kr/event/2025-0520/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250521T160000
DTEND;TZID=Asia/Seoul:20250521T173000
DTSTAMP:20260416T012412
CREATED:20250415T070417Z
LAST-MODIFIED:20250513T025423Z
UID:3767-1747843200-1747848600@ccg.ibs.re.kr
SUMMARY:Benjamin McMillan\, Secondary Characteristic classes and Chern-Weil theory of (Haefliger) singular foliations II
DESCRIPTION:    Speaker\n\n\nBenjamin McMillan\nIBS CCG\n\n\n\n\n\n\nFoliations have a theory of characteristic classes that is much like that of vector bundles\, but with notable differences. Some of the characteristic classes of a foliation come from its induced normal bundle\, but there are additional secondary classes that depend on more detailed information about the foliation. Just as with vector bundles\, one can obtain the characteristic classes using either a universal space or the Chern-Weil construction (in case the foliation is regular). \nIn these talks I will explain the general theory\, and how the Chern-Weil construction can often be made to work even for singular foliations.
URL:https://ccg.ibs.re.kr/event/2025-0521/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250522T110000
DTEND;TZID=Asia/Seoul:20250522T120000
DTSTAMP:20260416T012412
CREATED:20250415T070509Z
LAST-MODIFIED:20250513T025909Z
UID:3769-1747911600-1747915200@ccg.ibs.re.kr
SUMMARY:Benjamin McMillan\, Secondary Characteristic classes and Chern-Weil theory of (Haefliger) singular foliations III
DESCRIPTION:    Speaker\n\n\nBenjamin McMillan\nIBS CCG\n\n\n\n\n\n\nFoliations have a theory of characteristic classes that is much like that of vector bundles\, but with notable differences. Some of the characteristic classes of a foliation come from its induced normal bundle\, but there are additional secondary classes that depend on more detailed information about the foliation. Just as with vector bundles\, one can obtain the characteristic classes using either a universal space or the Chern-Weil construction (in case the foliation is regular). \nIn these talks I will explain the general theory\, and how the Chern-Weil construction can often be made to work even for singular foliations.
URL:https://ccg.ibs.re.kr/event/2025-0522-1/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250522T140000
DTEND;TZID=Asia/Seoul:20250522T150000
DTSTAMP:20260416T012412
CREATED:20250415T070802Z
LAST-MODIFIED:20250513T052302Z
UID:3773-1747922400-1747926000@ccg.ibs.re.kr
SUMMARY:Sanghyeon Lee\, Vafa-Witten invariants on elliptic surfaces and moduli space of quasisections
DESCRIPTION:    Speaker\n\n\nSanghyeon Lee\nAjou University\n\n\n\n\n\n\nFor a threefold X = C x S\, D. Nesterov developed a theory of quasimaps from C to the moduli space of sheaves over S. He compared the moduli space of quasimaps and the moduli space of sheaves over the threefold X and also compared their obstruction theories. \nWhen X is a smooth fibration over C\, I will explain how to generalize Nesterov’s theory by using a notion of quasisections\, instead of quasimap\, and the correspondence between moduli space of sheaves over X and the moduli space of quasisections to the relative moduli space of sheaves. As an application\, I will explain how to compute Vafa-Witten invariants of an elliptic surface\, which is a smooth fibration over C. \nMoreover\, for the case when the elliptic surface has nodal fibers\, we will discuss how we can generalize the theory of quasisections. This is based on an ongoing project with Yaoxiong Wen.
URL:https://ccg.ibs.re.kr/event/2025-0522/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
END:VCALENDAR