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PRODID:-//Center for Complex Geometry - ECPv6.15.20//NONSGML v1.0//EN
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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:20240101T000000
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BEGIN:VEVENT
DTSTART;VALUE=DATE:20250301
DTEND;VALUE=DATE:20260216
DTSTAMP:20260415T183337
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:20250326
DTEND;VALUE=DATE:20250503
DTSTAMP:20260415T183337
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:20250401T110000
DTEND;TZID=Asia/Seoul:20250401T120000
DTSTAMP:20260415T183337
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:20260415T183337
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:20260415T183337
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:20260415T183337
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:20260415T183337
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:20260415T183337
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:20260415T183337
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:20260415T183337
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:20260415T183337
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:20260415T183337
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
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