BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Center for Complex Geometry - ECPv6.15.20//NONSGML v1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-ORIGINAL-URL:https://ccg.ibs.re.kr
X-WR-CALDESC:Events for Center for Complex Geometry
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:20240101T000000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250301
DTEND;VALUE=DATE:20260216
DTSTAMP:20260416T025835
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;TZID=Asia/Seoul:20250514T110000
DTEND;TZID=Asia/Seoul:20250514T120000
DTSTAMP:20260416T025835
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:20260416T025835
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:20260416T025835
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:20260416T025835
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:20260416T025835
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:20260416T025835
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:20260416T025835
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
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250527T163000
DTEND;TZID=Asia/Seoul:20250527T173000
DTSTAMP:20260416T025835
CREATED:20250425T013928Z
LAST-MODIFIED:20250425T013928Z
UID:3786-1748363400-1748367000@ccg.ibs.re.kr
SUMMARY:Gian Pietro Pirola\, Sections of the Jacobian bundles of plane curves and applications
DESCRIPTION:    Speaker\n\n\nGian Pietro Pirola\nUniversity of Pavia\n\n\n\n\n\n\nWe study normal functions (sections of the Jacobian bundle) defined on the moduli space of pointed plane curves. Using the infinitesimal Griffiths invariant (refined by M. Green and C. Voisin) we show that a normal function with nontrivial but sufficiently “small” support cannot be “locally constant”. As an application\, we give a variational proof of the following result of Zu: \nTheorem: If C is a very general plane curve of degree d and C’ is any plane curve of degree d’\, then the cardinality i(C\, C’) of the intersection between C and C’ is > d-3. \nWe also show that if d > 3 and i(C\, C’) = d-2 then d’ = 1 and C’ is a bitangent or a flex line. For d = 4 this is a result of Chen\, Rield and Yeong. This is a joint work with Lorenzo Fassina.
URL:https://ccg.ibs.re.kr/event/2025-0527/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250608
DTEND;VALUE=DATE:20250615
DTSTAMP:20260416T025835
CREATED:20250616T073356Z
LAST-MODIFIED:20250616T074157Z
UID:3851-1749340800-1749945599@ccg.ibs.re.kr
SUMMARY:Han-Bom Moon (Fordham University)
DESCRIPTION:Han-Bom Moon\nVisitor (2025.6.8-2025.6.14) from Fordham University
URL:https://ccg.ibs.re.kr/event/250608-250614/
CATEGORIES:Visitors
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250609T163000
DTEND;TZID=Asia/Seoul:20250609T173000
DTSTAMP:20260416T025835
CREATED:20250420T041641Z
LAST-MODIFIED:20250420T041753Z
UID:3781-1749486600-1749490200@ccg.ibs.re.kr
SUMMARY:Han-Bom Moon\, Ulrich bundles on intersections of quadrics
DESCRIPTION:    Speaker\n\n\nHan-Bom Moon\nFordham University\n\n\n\n\n\n\nAn Ulrich bundle is a vector bundle with very strong cohomology vanishing conditions. Eisenbud and Schreyer conjectured that every smooth projective variety possesses an Ulrich bundle. Despite many results on low dimensional varieties and special varieties\, the general existence is unknown. In this talk\, I will describe recent work in progress with Kyoung-Seog Lee and Jiwan Jeong on the construction of Ulrich bundles on an intersection of quadrics.
URL:https://ccg.ibs.re.kr/event/2025-0609/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250623
DTEND;VALUE=DATE:20250706
DTSTAMP:20260416T025835
CREATED:20250616T073537Z
LAST-MODIFIED:20250616T074129Z
UID:3853-1750636800-1751759999@ccg.ibs.re.kr
SUMMARY:Patrick Brosnan (University of Maryland)
DESCRIPTION:Patrick Brosnan\nVisitor (2025.6.23-2025.7.5) from University of Maryland
URL:https://ccg.ibs.re.kr/event/250623-250705/
CATEGORIES:Visitors
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250624T163000
DTEND;TZID=Asia/Seoul:20250624T173000
DTSTAMP:20260416T025835
CREATED:20250521T065127Z
LAST-MODIFIED:20250521T065607Z
UID:3820-1750782600-1750786200@ccg.ibs.re.kr
SUMMARY:Sung Gi Park\, Hodge symmetries of singular varieties
DESCRIPTION:    Speaker\n\n\nSung Gi Park\nPrinceton U. / IAS\n\n\n\n\n\n\nThe Hodge diamond of a smooth projective complex variety exhibits fundamental symmetries\, arising from Poincaré duality and the purity of Hodge structures. In the case of a singular projective variety\, the complexity of the singularities is closely related to the symmetries of the analogous Hodge-Du Bois diamond. For example\, the failure of the first nontrivial Poincaré duality is reflected in the defect of factoriality. Based on joint work with Mihnea Popa\, I will discuss how local and global conditions on singularities influence the topology of algebraic varieties.
URL:https://ccg.ibs.re.kr/event/2025-0624/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250625
DTEND;VALUE=DATE:20250706
DTSTAMP:20260416T025835
CREATED:20250616T073703Z
LAST-MODIFIED:20250616T074057Z
UID:3855-1750809600-1751759999@ccg.ibs.re.kr
SUMMARY:Alex Abreu (Universidade Federal Fluminense)
DESCRIPTION:Alex Abreu\nVisitor (2025.6.25-2025.7.5) from Universidade Federal Fluminense
URL:https://ccg.ibs.re.kr/event/250625-250705/
CATEGORIES:Visitors
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250626T163000
DTEND;TZID=Asia/Seoul:20250626T173000
DTSTAMP:20260416T025835
CREATED:20250601T044122Z
LAST-MODIFIED:20250601T044122Z
UID:3844-1750955400-1750959000@ccg.ibs.re.kr
SUMMARY:Yoosik Kim\, Disk Counting via GIT Quotients
DESCRIPTION:    Speaker\n\n\nYoosik Kim\nPusan National University\n\n\n\n\n\n\nAccording to the Kempf–Ness theorem\, the GIT quotient is equivalent to the symplectic reduction. Using this correspondence\, we explain how to relate the counting of holomorphic disks between a symplectic manifold equipped with a Hamiltonian group action and its symplectic reduction. As an application\, we derive the disk potential function for weight varieties obtained as quotients by the maximal torus of partial flag varieties. We also demonstrate how the disk counting depends on the choice of stability conditions.
URL:https://ccg.ibs.re.kr/event/2025-0626/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250627T110000
DTEND;TZID=Asia/Seoul:20250627T120000
DTSTAMP:20260416T025835
CREATED:20250402T105322Z
LAST-MODIFIED:20250616T073823Z
UID:3739-1751022000-1751025600@ccg.ibs.re.kr
SUMMARY:Alex Abreu\, On the Torelli Theorem for graphs and stable curves
DESCRIPTION:    Speaker\n\n\nAlex Abreu\nUniversidade Federal Fluminense\n\n\n\n\n\n\nThe classical Torelli theorem states that a smooth curve can be recovered from its polarized Jacobian. In this talk\, we will discuss the extensions of this theorem to stable curves and their dual graphs\, as well as its dependence on the concept of compactified Jacobians. First\, we will recall Caporaso and Viviani’s theorem\, which characterizes when two stable curves have the same Caporaso’s compactified Jacobian. Then we will discuss Torelli’s theorem via fine compactified Jacobians. This is based on an ongoing joint work with Marco Pacini and Nicola Pagani.
URL:https://ccg.ibs.re.kr/event/2025-0627/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20250630
DTEND;VALUE=DATE:20250705
DTSTAMP:20260416T025835
CREATED:20250523T025625Z
LAST-MODIFIED:20250703T054133Z
UID:3825-1751241600-1751673599@ccg.ibs.re.kr
SUMMARY:Workshop on Hessenberg varieties\, Lusztig varieties\, and Affine Grassmannians
DESCRIPTION:  \nThis workshop brings together experts in Hessenberg varieties\, Lusztig varieties\, and the affine Grassmannian. It focuses on the rich interactions among these geometric objects and their connections to representation theory and combinatorics. Recent breakthroughs and new developments will be presented and discussed. The workshop aims to foster collaboration and inspire future research. \nInvited Speakers\nLectures \nAlex Abreu (Universidade Federal Fluminense)\nPramod Achar (Louisiana State University) * \nResearch Talks \nHiraku Abe (Okayama University of Science)\nDonggun Lee (IBS CCG) \n* (online) \nAbstracts\nPDF file \nLecture Note\nPramod Achar (Louisiana State University): Notability link \nSchedule\nMonday (June 30) \n10:00-11:00 Alex Abreu\n11:30-12:30 Pramod Achar\n12:30-14:00 Lunch\n14:00-16:00 Open Problems\n16:00-18:00 Tea Break/Free Discussion\n18:00- Speakers Dinner \nTuesday (July 1) \n10:00-11:00 Alex Abreu\n11:30-12:30 Pramod Achar\n12:30-14:00 Lunch\n14:00-16:00 Free Discussion\n16:00-18:00 Tea Break/Free Discussion\n18:00- Banquet \nWednesday (July 2) \n10:00-11:00 Alex Abreu\n11:30-12:30 Pramod Achar\n12:30-14:00 Lunch\n14:00-16:00 Free Discussion\n16:00-18:00 Tea Break/Free Discussion\n18:00- Speakers Dinner \nThursday (July 3) \n10:00-11:00 Donggun Lee\n11:30-12:30 Hiraku Abe\n12:30-14:00 Lunch \nFriday (July 4) \n10:00-12:00 Open Problems\n12:30-14:00 Lunch \nOrganizers\nPatrick Brosnan (University of Maryland)\nJaehyun Hong (IBS CCG)\nDonggun Lee (IBS CCG) \nVenue\nB109\, IBS\, Daejeon\, Korea \nRegistration\nPlease submit Google form by June 26 (Thu).\nThere will be open problem sessions. To suggest open problems/questions\, complete google form by June 23 (Mon). \nMore Information\n• How to get to IBS-CCG
URL:https://ccg.ibs.re.kr/event/2025-0630-0704/
LOCATION:B109\, IBS\, Korea\, Republic of
CATEGORIES:Conferences and Workshops
ATTACH;FMTTYPE=image/jpeg:https://ccg.ibs.re.kr/wp-content/uploads/2025/07/group-photo1_small.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250702T150000
DTEND;TZID=Asia/Seoul:20250702T160000
DTSTAMP:20260416T025835
CREATED:20250625T055648Z
LAST-MODIFIED:20250625T055905Z
UID:3880-1751468400-1751472000@ccg.ibs.re.kr
SUMMARY:Yoonjoo Kim\, Two results on Lagrangian fibrations
DESCRIPTION:    Speaker\n\n\nYoonjoo Kim\nColumbia U.\n\n\n\n\n\n\nI would like to report two ongoing results on Lagrangian fibrations of smooth symplectic varieties. The first is the construction of a delta-regular smooth group scheme that acts on a given Lagrangian fibration. It is a generalization of the result of Arinkin-Fedorov\, who proved the result under the assumption that every fiber is integral. The second is the computation of the degree of the discriminant divisor of a Lagrangian fibration\, assuming the total space is a (projective) hyper-Kähler manifold. This resolves a question raised by Sawon\, who first discovered the formula and proved it under the assumption that every general singular fiber is integral. The first result is joint work with Mark de Cataldo and Christian Schnell.
URL:https://ccg.ibs.re.kr/event/2025-0702/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250807T140000
DTEND;TZID=Asia/Seoul:20250807T150000
DTSTAMP:20260416T025835
CREATED:20250721T120346Z
LAST-MODIFIED:20250721T120346Z
UID:3933-1754575200-1754578800@ccg.ibs.re.kr
SUMMARY:Hyukmoon Choi\, Equivariant compactification structures on smooth projective horospherical varieties of Picard number 1
DESCRIPTION:    Speaker\n\n\nHyukmoon Choi\nIBS CCG and KAIST\n\n\n\n\n\n\nA projective variety V is an equivariant compactification of an algebraic group G if there exists an algebraic G-action on V with a Zariski open orbit O\, which is equivariantly biregular to G. Such a G-action is called an equivariant compactification (EC) structure on V. For a smooth nonhomogeneous projective horospherical variety X of Picard number 1\, and for a suitable nilpotent subgroup N of the automorphism group of X\, we show that X admits an EC structure of N and that any two EC structures of N on X are isomorphic.
URL:https://ccg.ibs.re.kr/event/2025-0807/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250827T163000
DTEND;TZID=Asia/Seoul:20250827T173000
DTSTAMP:20260416T025835
CREATED:20250807T081010Z
LAST-MODIFIED:20250807T081429Z
UID:3987-1756312200-1756315800@ccg.ibs.re.kr
SUMMARY:Makoto Enokizono\, Normal stable degenerations of Noether-Horikawa surfaces
DESCRIPTION:    Speaker\n\n\nMakoto Enokizono\nUniversity of Tokyo\n\n\n\n\n\n\nNoether-Horikawa surfaces are surfaces of general type satisfying the equation K2=2pg−4\, which represents the equality of the Noether inequality K2≥2pg−4 for surfaces of general type. In the 1970s\, Horikawa conducted a detailed study of smooth Noether-Horikawa surfaces\, providing a classification of these surfaces and describing their moduli spaces.\nIn this talk\, I will present an explicit classification of normal stable degenerations of Noether-Horikawa surfaces. Specifically\, I will discuss the following results:\n(1) Classification of Noether-Horikawa surfaces with Q-Gorenstein smoothable log canonical singularities.\n(2) Criterion for determining the (global) Q-Gorenstein smoothability of the surfaces described in (1).\n(3) Description of the KSBA moduli spaces for Q-Gorenstein smoothable normal stable Noether-Horikawa surfaces.\nThis is joint work with Hiroto Akaike\, Masafumi Hattori and Yuki Koto.
URL:https://ccg.ibs.re.kr/event/2025-0827/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250828T150000
DTEND;TZID=Asia/Seoul:20250828T160000
DTSTAMP:20260416T025835
CREATED:20250731T053718Z
LAST-MODIFIED:20250807T081201Z
UID:3972-1756393200-1756396800@ccg.ibs.re.kr
SUMMARY:Doyoung Choi\, Singularities and syzygies of secant varieties of smooth projective varieties
DESCRIPTION:    Speaker\n\n\nDoyoung Choi\nKAIST / IBS\n\n\n\n\n\n\nWe study the higher secant varieties of a smooth projective variety embedded in projective space. We prove that when the variety is a surface and the embedding line bundle is sufficiently positive\, these varieties are normal with Du Bois singularities and the syzygies of their defining ideals are linear to the expected order. We show that the cohomology of the structure sheaf of the surface completely determines whether the singularities of its secant varieties are Cohen-Macaulay or rational. We also prove analogous results when the dimension of the original variety is higher and the secant order is low\, and by contrast we prove a result that strongly implies these statements do not generalize to higher dimensional varieties when the secant order is high. Finally\, we deduce a complementary result characterizing the ideal of secant varieties of a surface in terms of the symbolic powers of the ideal of the surface itself\, and we include a theorem concerning the weight one syzygies of an embedded surface — analogous to the gonality conjecture for curves — which we discovered as a natural application of our techniques.
URL:https://ccg.ibs.re.kr/event/2025-0828/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250828T163000
DTEND;TZID=Asia/Seoul:20250828T173000
DTSTAMP:20260416T025835
CREATED:20250731T053916Z
LAST-MODIFIED:20250807T081139Z
UID:3975-1756398600-1756402200@ccg.ibs.re.kr
SUMMARY:Haesong Seo\, Algebraic hyperbolicity of adjoint linear systems on spherical varieties
DESCRIPTION:    Speaker\n\n\nHaesong Seo\nKAIST / IBS\n\n\n\n\n\n\nA projective manifold is called hyperbolic if it does not admit an entire map from the complex plane. Demailly proved that hyperbolic manifolds are algebraically hyperbolic\, meaning that there are degree bounds for curves in terms of their genera. It is a highly challenging problem to determine whether a given variety is algebraically hyperbolic or not. In this talk\, we prove that a very general hypersurface in an adjoint linear system on a spherical variety is algebraically hyperbolic outside the boundary. This is based on a joint work with Dr. Minseong Kwon.
URL:https://ccg.ibs.re.kr/event/2025-0828-2/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250911T140000
DTEND;TZID=Asia/Seoul:20250911T150000
DTSTAMP:20260416T025835
CREATED:20250811T073750Z
LAST-MODIFIED:20250811T075032Z
UID:4005-1757599200-1757602800@ccg.ibs.re.kr
SUMMARY:Qifeng Li\, Minimal rational curves on equivariant compactifications of symmetric spaces
DESCRIPTION:    Speaker\n\n\nQifeng Li\nShandong University\n\n\n\n\n\n\nLet X be a smooth equivariant compactification of a symmetric space. In this talk\, we will discuss when a minimal rational curve on X is the orbit closure of a 1-parameter group. In case the symmetric space is of group type\, the answer is positive and moreover the VMRT is the closure of an adjoint orbit. This generalizes a result of Brion and Fu’s on wonderful compactifications to arbitrary equivariant compactifications. This is a joint work with Jun-Muk Hwang.
URL:https://ccg.ibs.re.kr/event/2025-0911/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20250911T160000
DTEND;TZID=Asia/Seoul:20250911T170000
DTSTAMP:20260416T025835
CREATED:20250811T074515Z
LAST-MODIFIED:20250811T075048Z
UID:4009-1757606400-1757610000@ccg.ibs.re.kr
SUMMARY:Yong Hu\, Moduli spaces of threefolds on the Noether line
DESCRIPTION:    Speaker\n\n\nYong Hu\nShanghai Jiao Tong University\n\n\n\n\n\n\nIn this talk\, we will introduce the 3-dimensional Noether inequality and completely classify the canonical threefolds on the Noether line with $p_g \ge 5$ by studying their moduli spaces. For every such moduli space\, we establish an explicit stratification\, estimate the number of its irreducible components and prove the dimension formula. A new and unexpected phenomenon is that the number of irreducible components grows linearly with the geometric genus\, while the moduli space of canonical surfaces on the Noether line with any prescribed geometric genus has at most two irreducible components of the same dimension. This is a joint work with S.Coughlan\, R.Pignatelli and T.Zhang.
URL:https://ccg.ibs.re.kr/event/2025-0911-2/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20251002T140000
DTEND;TZID=Asia/Seoul:20251002T150000
DTSTAMP:20260416T025835
CREATED:20250924T152103Z
LAST-MODIFIED:20251030T163023Z
UID:4107-1759413600-1759417200@ccg.ibs.re.kr
SUMMARY:Minseong Kwon\, Automorphism groups of toroidal horospherical varieties
DESCRIPTION:    Speaker\n\n\nMinseong Kwon\nGyeongsang National University\n\n\n\n\n\n\nIn the 1970s\, Demazure studied the automorphism groups of two types of almost homogeneous varieties: rational homogeneous spaces and toric varieties. Especially\, for a smooth complete toric variety\, Demazure obtained a structure theorem for the connected automorphism group in terms of the so-called Demazure roots. In this talk\, I will discuss the connected automorphism group of a smooth complete toroidal horospherical variety\, which can be viewed as a fiber bundle over a rational homogeneous space with toric fibers. Namely\, I will introduce a notion of roots as a generalization of the Demazure roots\, and then utilize it to describe the structure of the connected automorphism group. As a consequence\, a reductivity criterion for the connected automorphism group will be presented. This talk is based on a joint work with Lorenzo Barban and DongSeon Hwang.
URL:https://ccg.ibs.re.kr/event/2025-1002/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20251103
DTEND;VALUE=DATE:20251108
DTSTAMP:20260416T025835
CREATED:20250707T061146Z
LAST-MODIFIED:20251106T052306Z
UID:3901-1762128000-1762559999@ccg.ibs.re.kr
SUMMARY:Moduli of Surfaces and Beyond
DESCRIPTION:  \nSpeakers\nLecture Series (3hr) \nRadu Laza (Stony Brook University)\nMatthias Schütt (Leibniz Universität Hannover)\nJenia Tevelev (University of Massachusetts Amherst) \nResearch Talks (1hr) \nKenneth Ascher (University of California\, Irvine)\nDori Bejleri (University of Maryland\, College Park)\nHarold Blum (Georgia Institute of Technology)\nNathan Chen (Harvard University)\nChangho Han (Korea University)\nDonggun Lee (IBS-CCG)\nSamouil Molcho (Sapienza Università di Roma)\nGiancarlo Urzua (Pontificia Universidad Católica de Chile) \nAbstracts\nPDF file \nSchedule\n\n\n\n\nMon\nTue\nWed\nThu\nFri\n\n\n10:00~11:00\nRegistration\nSchütt 2\nSchütt 3\nUrzua\nHan\n\n\n11:00~11:30\nCoffee break\nCoffee break\nCoffee break\nCoffee break\nCoffee break\n\n\n11:30~12:30\nSchütt 1\nLaza 2\nLaza 3\nAscher\nChen\n\n\n12:30~14:30\nLunch\nLunch\nLunch\nLunch\nLunch\n\n\n14:30~15:30\nLaza 1\nTevelev 2\nTevelev 3\nBejleri\nLee\n\n\n15:30~16:00\nCoffee break\nCoffee break\nCoffee break\nCoffee break\n\n\n\n16:00~17:00\nTevelev 1\nMolcho\n\nBlum\n\n\n\n17:30~20:00\nDinner for Speakers\nBanquet\nDinner for Speakers\nDinner for Speakers\n\n\n\n\nOrganizers\nDongSeon Hwang (IBS-CCG)\nDonggun Lee (IBS-CCG)\nYongnam Lee (IBS-CCG) \nVenue\nIBS Science Culture Center\, Daejeon\, Korea \nRegistration\nPlease submit Google form by October 15. \nMain Hotel\nLotte City Hotel Daejeon (4-30 Doryong-dong\, Yuseong-gu\, Daejeon) \nMore Information\n• How to get to IBS-CCG\n• From Hotel to IBS
URL:https://ccg.ibs.re.kr/event/2025-1103-1107/
LOCATION:IBS Science Culture Center\, Daejeon\, Korea\, Republic of
CATEGORIES:Conferences and Workshops
ATTACH;FMTTYPE=image/jpeg:https://ccg.ibs.re.kr/wp-content/uploads/2025/11/group-photo1-2-scaled.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20251211T160000
DTEND;TZID=Asia/Seoul:20251211T170000
DTSTAMP:20260416T025835
CREATED:20251030T162814Z
LAST-MODIFIED:20251030T162814Z
UID:4187-1765468800-1765472400@ccg.ibs.re.kr
SUMMARY:Cauchy-Riemann Symmetry and Real Hypersurfaces in Hermitian Symmetric Spaces
DESCRIPTION:    Speaker\n\n\nJong Taek Cho\nChonnam National University\n\n\n\n\n\n\nWe survey recent developments of pseudo-Hermitian geometry or CR geometry of hypersurface type\, with a particular focus on their symmetries and realizations as real hypersurfaces in Hermitian symmetric spaces.
URL:https://ccg.ibs.re.kr/event/2025-1211/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Several Complex Variables Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20251215
DTEND;VALUE=DATE:20251220
DTSTAMP:20260416T025835
CREATED:20251002T043542Z
LAST-MODIFIED:20251224T074545Z
UID:4114-1765756800-1766188799@ccg.ibs.re.kr
SUMMARY:Perspectives in algebraic geometry
DESCRIPTION:The talks will begin on December 16\, following a day of free discussion on December 15. \nConfirmed Speakers\nLorenzo Barban (IBS-CCG)\nJunho Choe (KIAS)\nKarl Christ (University of Turin)\nFei Hu (Nanjing University)\nSukmoon Huh (Sungkyunkwan University)\nJaehyun Kim (Ewha Womans University)\nJeong-Seop Kim (KIAS)\nShin-Young Kim (Kangwon National University)\nHaidong Liu (Sun Yat-sen University)\nWenfei Liu (Xiamen University)\nGebhard Martin (University of Bonn)\nSheng Meng (ECNU)\nSung Gi Park (Princeton University)\nLuca Rizzi (IBS-CGP)\nHaesong Seo (KAIST/IBS-CCG)\nLei Song (Sun Yat-sen University)\nClaudia Stadlmayr (University of Neuchâtel)\nSho Tanimoto (Nagoya University)\nWern Yeong (UCLA) \nAbstracts\nPDF file \nSchedule\n\n\n\n\nMon\nTue\nWed\nThu\nFri\n\n\n09:30~10:00\nFree discussion & seminar (TBA)\nRegistration\n\n\n\n\n\n10:00~10:50\nKarl christ\nLei Song\nSukmoon Huh\nWern Yeong\n\n\n11:10~12:00\nSung Gi Park\nJunho Choe\nWenfei Liu\nHaesong Seo\n\n\n12:00~14:00\nLunch\nLunch\nLunch\nLunch\n\n\n14:00~14:50\nLorenzo Barban\nClaudia Stadlmayr\nJeong-Seop Kim\nLuca Rizzi\n\n\n15:10~16:00\nShin-young Kim\nFei Hu\nJaehyun Kim\nGebhard Martin\n\n\n16:20~17:10\nHaidong Liu\nSheng Meng\nSho Tanimoto\n\n\n\n17:40~20:00\nDinner for Speakers\nBanquet\nDinner for Speakers\nDinner for Speakers\n\n\n\n(There will be a coffee/tea break between talks each day.) \nOrganizers\nDongSeon Hwang (IBS-CCG)\nJun-Muk Hwang (IBS-CCG)\nYongnam Lee (IBS-CCG) \nVenue\nB109\, IBS \nRegistration\nPlease submit Google form by November 30. \nMain Hotel\nLotte City Hotel Daejeon (4-30 Doryong-dong\, Yuseong-gu\, Daejeon) \nMore Information\n• How to get to IBS-CCG\n• From Hotel to IBS
URL:https://ccg.ibs.re.kr/event/2025-12-16-19/
LOCATION:B109\, IBS\, Korea\, Republic of
CATEGORIES:Conferences and Workshops
ATTACH;FMTTYPE=image/jpeg:https://ccg.ibs.re.kr/wp-content/uploads/2025/12/20251217_172320211-scaled.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20251215T163000
DTEND;TZID=Asia/Seoul:20251215T173000
DTSTAMP:20260416T025835
CREATED:20251204T142011Z
LAST-MODIFIED:20251204T142011Z
UID:4293-1765816200-1765819800@ccg.ibs.re.kr
SUMMARY:Enriques surfaces of zero entropy
DESCRIPTION:    Speaker\n\n\nGebhard Martin\nUniversity of Bonn\n\n\n\n\n\n\nThe automorphism group of a general Enriques surface is the 2-congruence subgroup of the Weyl group of the E10-lattice. In particular\, it is infinite and not virtually solvable. On the other end of the spectrum\, there do exist Enriques surfaces with finite automorphism group\, first classified over the complex numbers by Nikulin and Kondo. In this talk\, I will explain the classification of Enriques surfaces with infinite and virtually Abelian automorphism group. This is joint work with Giacomo Mezzedimi and Davide Veniani.
URL:https://ccg.ibs.re.kr/event/enriques-surfaces-of-zero-entropy/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20251229T160000
DTEND;TZID=Asia/Seoul:20251229T173000
DTSTAMP:20260416T025835
CREATED:20251116T142453Z
LAST-MODIFIED:20251116T142453Z
UID:4236-1767024000-1767029400@ccg.ibs.re.kr
SUMMARY:Kyoung-Seog Lee\, On intersection of two quadrics I
DESCRIPTION:    Speaker\n\n\nKyoung-Seog Lee\nPOSTECH\n\n\n\n\n\n\nIntersections of two quadrics form an interesting class of algebraic varieties and they have been intensively studied from various aspects. In these talks\, I will discuss these various aspects of the intersection of two quadrics and how to interpret/generalize some of the classical algebraic geometry results using the derived category of coherent sheaves. The last part of these talks is based on a joint work in progress with Jiwan Jung and Han-Bom Moon.
URL:https://ccg.ibs.re.kr/event/kyoung-seog-lee-on-intersection-of-two-quadrics-i/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
END:VCALENDAR