BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Center for Complex Geometry - ECPv6.15.20//NONSGML v1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:Center for Complex Geometry
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:20220101T000000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;VALUE=DATE:20240115
DTEND;VALUE=DATE:20240120
DTSTAMP:20260416T043940
CREATED:20230909T052951Z
LAST-MODIFIED:20240121T235022Z
UID:2517-1705276800-1705708799@ccg.ibs.re.kr
SUMMARY:Workshop on Torus Actions in Symplectic and Algebraic Geometry
DESCRIPTION:Lecture Series\nKiumars Kaveh (University of Pittsburgh)\nHendrik Süß (University of Jena)*\nSusan Tolman (University of Illinois at Urbana-Champaign) \nResearch Talks\nLara Bossinger (UNAM)\nIsabelle Charton (University of Haifa)\nOliver Clarke (University of Edinburgh)\nPeter Crooks (Utah State University)\nNaoki Fujita (Kumamoto University)\nYoosik Kim (Pusan National University)\nDonggun Lee (IBS CCG)\nJoseph Palmer (University of Illinois at Urbana-Champaign)\nAndrea Petracci (Università di Bologna)\nMilena Wrobel (University of Oldenburg) \n* = online \nAbstracts\nWebsite \nSchedule\n\n\n\n\nMonday\nTuesday\nWednesday\nThursday\nFriday\n\n\n9:40 – 10:40\n\nKaveh 2\nKaveh 4\nBossinger\nKim\n\n\n11:10 – 12:10\n\nTolman 2\nTolman 3\nClarke\nCharton\n\n\n12:20 – 14:00\n\nLunch\nLunch\nLunch\nLunch\n\n\n14:00 -15:00\nKaveh 1\nKaveh 3\nFujita\nPetracci\nPalmer\n\n\n15:30 – 16:30\nTolman 1\n5-minute talks\nLee\nWrobel\nCrooks\n\n\n17:00 – 18:00\nSüß 1\nSüß 2\nSüß 3\nSüß 4\n\n\n\n\n\n\nBanquet\n\n\n\n\n\nOrganizers\nYunhyung Cho (Sungkyunkwan University)\nJaehyun Hong (IBS CCG)\nDonghoon Jang (Pusan National University)\nEunjeong Lee (Chungbuk National University) \nVenue\nIBS Science Culture Center \nRegistration\nPlease submit Google form by December 17. \nPoster\nPDF file \nMore Information\n• How to get to IBS-CCG\n• Accommodations\n• Restaurants
URL:https://ccg.ibs.re.kr/event/2024-01-15-19/
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/2024/01/Group-photo2-scaled.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20231212
DTEND;VALUE=DATE:20231216
DTSTAMP:20260416T043940
CREATED:20230808T010107Z
LAST-MODIFIED:20251002T043239Z
UID:2467-1702339200-1702684799@ccg.ibs.re.kr
SUMMARY:Workshop on Classical Algebraic Geometry
DESCRIPTION:Speakers\nAlberto Calabri (University of Ferrara)\nCinzia Casagrande (University of Torino)\nFlaminio Flamini (University of Rome Tor Vergata)\nPaola Frediani (University of Pavia)\nKangjin Han (DGIST)\nZhi Jiang (SCMS\, Fudan University)\nAkihiro Kanemitsu (Saitama University)\nGrzegorz Kapustka (Jagiellonian University)\nMichał Kapustka (IM PAN)\nSeonja Kim (Chungwoon University)\nHirokazu Nasu (Tokai University)\nWenbo Niu (University of Arkansas)\nJinhyung Park (KAIST)\nXavier Roulleau (University of Angers)\nFrancesco Russo (University of Catania)\nEduardo Luis Solá Conde (University of Trento) \nAbstracts\nPDF file \nSchedule\nDecember 12 (Tuesday) \n\n\n\n09:30~10:00\nRegistration\n\n\n10:00~11:00\nCinzia Casagrande\n\n\n11:00~11:30\nCoffee Break\n\n\n11:30~12:30\nJinhyung Park\n\n\n12:30~14:30\nLunch\n\n\n14:30~15:30\nSeonja Kim\n\n\n15:30~16:00\nCoffee Break\n\n\n16:00~17:00\nEduardo Luis Solá Conde\n\n\n18:00~20:00\nDinner for Speakers\n\n\n\n  \nDecember 13 (Wednesday) \n\n\n\n10:00~11:00\nFlaminio Flamini\n\n\n11:00~11:30\nCoffee Break\n\n\n11:30~12:30\nHirokazu Nasu\n\n\n12:30~14:30\nLunch\n\n\n14:30~15:30\nZhi Jiang\n\n\n15:30~16:00\nCoffee Break\n\n\n16:00~17:00\nAkihiro Kanemitsu\n\n\n\n  \nDecember 14 (Thursday) \n\n\n\n10:00~11:00\nMichał Kapustka\n\n\n11:00~11:30\nCoffee Break\n\n\n11:30~12:30\nGrzegorz Kapustka\n\n\n12:30~14:30\nLunch\n\n\n14:30~15:30\nAlberto Calabri\n\n\n15:30~16:00\nCoffee Break\n\n\n16:00~17:00\nFrancesco Russo\n\n\n17:30~20:00\nBanquet\n\n\n\n  \nDecember 15 (Friday) \n\n\n\n10:00~11:00\nXavier Roulleau\n\n\n11:00~11:30\nCoffee Break\n\n\n11:30~12:30\nWenbo Niu\n\n\n12:30~14:00\nLunch\n\n\n14:00~15:00\nKangjin Han\n\n\n15:00~15:30\nCoffee Break\n\n\n15:30~16:30\nPaola Frediani\n\n\n\nOrganizers\nDongSeon Hwang (IBS-CCG)\nJun-Muk Hwang (IBS-CCG)\nYongnam Lee (IBS-CCG/KAIST) \nVenue\nIBS Science Culture Center \nRegistration\nPlease submit Google form by November 10th. \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/2023-12-12-15/
LOCATION:IBS Science Culture Center\, Daejeon\, Korea\, Republic of
CATEGORIES:Conferences and Workshops
ATTACH;FMTTYPE=image/png:https://ccg.ibs.re.kr/wp-content/uploads/2023/12/Photo.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20231211T160000
DTEND;TZID=Asia/Seoul:20231211T170000
DTSTAMP:20260416T043940
CREATED:20231107T104342Z
LAST-MODIFIED:20231205T114256Z
UID:2625-1702310400-1702314000@ccg.ibs.re.kr
SUMMARY:Grzegorz Kapustka\, Projective Models of Nikulin Orbifolds
DESCRIPTION:    Speaker\n\n\nGrzegorz Kapustka\nJagiellonian University\n\n\n\n\n\n\nWe describe a locally complete family of projective irreducible holomorphic symplectic orbifolds as double covers of special complete intersections (3\, 4) in P6. This is a joint work with C. Camere\, A. Garbagnati and M. Kapustka.
URL:https://ccg.ibs.re.kr/event/2023-12-11-1600-1700/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20231122T150000
DTEND;TZID=Asia/Seoul:20231122T173000
DTSTAMP:20260416T043940
CREATED:20231030T014452Z
LAST-MODIFIED:20231030T014452Z
UID:2613-1700665200-1700674200@ccg.ibs.re.kr
SUMMARY:Andreas Höring\, Projective Manifolds with Pseudoeffective (Co)tangent Bundle\, III\, IV
DESCRIPTION:    Speaker\n\n\nAndreas Höring\nUniversity of Nice\n\n\n\n\n\n\nSymmetric holomorphic forms on projective manifolds have been studied from various angles in the last ten years : Brotbek-Darondeau and independently Song-Yan Xie have shown that complete intersections of sufficiently high degree and codimension have an ample cotangent bundle\, so many symmetric forms. Vice versa Campana and Paun show that if the cotangent bundle is big\, then X is of general type. In this series of lectures I will work under the assumption that the cotangent bundle is pseudoeffective. In general this positivity assumption is too weak to have any useful implications\, but we will see that for the (co)tangent bundle it leads to surprisingly many restrictions on the geometry of the manifold. In particular we expect a nonvanishing property that is analogous to the famous nonvanishing conjecture for the canonical bundle. These talks are based on joint papers with Thomas Peternell and Junyan Cao.
URL:https://ccg.ibs.re.kr/event/2023-11-22/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20231120T150000
DTEND;TZID=Asia/Seoul:20231120T173000
DTSTAMP:20260416T043940
CREATED:20231030T014336Z
LAST-MODIFIED:20231030T014336Z
UID:2611-1700492400-1700501400@ccg.ibs.re.kr
SUMMARY:Andreas Höring\, Projective Manifolds with Pseudoeffective (Co)tangent Bundle\, I\, II
DESCRIPTION:    Speaker\n\n\nAndreas Höring\nUniversity of Nice\n\n\n\n\n\n\nSymmetric holomorphic forms on projective manifolds have been studied from various angles in the last ten years : Brotbek-Darondeau and independently Song-Yan Xie have shown that complete intersections of sufficiently high degree and codimension have an ample cotangent bundle\, so many symmetric forms. Vice versa Campana and Paun show that if the cotangent bundle is big\, then X is of general type. In this series of lectures I will work under the assumption that the cotangent bundle is pseudoeffective. In general this positivity assumption is too weak to have any useful implications\, but we will see that for the (co)tangent bundle it leads to surprisingly many restrictions on the geometry of the manifold. In particular we expect a nonvanishing property that is analogous to the famous nonvanishing conjecture for the canonical bundle. These talks are based on joint papers with Thomas Peternell and Junyan Cao.
URL:https://ccg.ibs.re.kr/event/2023-11-20/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20231101T150000
DTEND;TZID=Asia/Seoul:20231101T160000
DTSTAMP:20260416T043940
CREATED:20231024T124300Z
LAST-MODIFIED:20231024T124300Z
UID:2602-1698850800-1698854400@ccg.ibs.re.kr
SUMMARY:Seungjae Lee\, Cohomological Isomorphism of Symmetric Power of Cotangent Bundle of Ball Quotient and its Toroidal Compactification
DESCRIPTION:    Speaker\n\n\nSeungjae Lee\nIBS CCG\n\n\n\n\n\n\nIn this talk\, we investigate the L2-Dolbeault cohomology of the symmetric power of cotangent bundles of ball quotients with finite volume\, as well as their toroidal compactification. As a result\, we establish a version of L2-Hodge decompostion for complex hyperbolic space forms with finite volume\, under some mild condition for lattice.
URL:https://ccg.ibs.re.kr/event/2023-11-01/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Several Complex Variables Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20231025T110000
DTEND;TZID=Asia/Seoul:20231025T120000
DTSTAMP:20260416T043940
CREATED:20231022T054758Z
LAST-MODIFIED:20231022T054814Z
UID:2594-1698231600-1698235200@ccg.ibs.re.kr
SUMMARY:Yotsutani Naoto\, Chow Stability and Non-symmetric Kähler-Einstein Toric Fano Manifolds
DESCRIPTION:    Speaker\n\n\nYotsutani Naoto\nKagawa University\n\n\n\n\n\n\nIn 2001\, Donaldson proved that if a polarized manifold (X\, L) admits constant scalar curvature Kähler metrics in c1(L)\, then (X\, L) is asymptotically Chow stable whenever its automorphism group Aut(X\, L) is discrete. \nIn this talk\, we show that this result does not hold in the case where Aut(X\, L) is not discrete. \nThis talk is based on a joint work with H. Ono and Y. Sano.
URL:https://ccg.ibs.re.kr/event/2023-10-25/
LOCATION:B266\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20231017
DTEND;VALUE=DATE:20231021
DTSTAMP:20260416T043940
CREATED:20230725T012006Z
LAST-MODIFIED:20231022T055239Z
UID:2391-1697500800-1697846399@ccg.ibs.re.kr
SUMMARY:Workshop on Parabolic Geometry and Related Topics
DESCRIPTION:Speakers\nGil Bor (CIMAT)\nAndreas Cap (U. Vienna)\nSean Curry (Oklahoma State U.)\nMike Eastwood (U. Adelaide)\nJaehyun Hong (IBS-CCG)\nJun-Muk Hwang (IBS-CCG)\nSung Yeon Kim (IBS-CCG)\nIlya Kossovskiy (Masaryk U.)\nBoris Kruglikov (U. Tromso)\nOmid Makhmali (PAS-CTP)\nBenjamin McMillan (IBS-CCG)\nTohru Morimoto (Nara Women’s U.)\nIgor Zelenko (Texas A&M) \nAbstracts\nPDF file \nSchedule\nOct. 17 \n10:00-11:00 Igor Zelenko\n11:30-12:30 Ilya Kossovskiy\n15:00-16:00 Gil Bor\n16:30-17:30 Sung Yeon Kim \nOct. 18 \n10:00-11:00 Andreas Cap\n11:30-12:30 Jun-Muk Hwang\n14:30-15:30 Benjamin McMillan \nOct. 19 \n10:00-11:00 Sean Curry\n11:30-12:30 Omid Makhmali\n15:00-16:00 Tohru Morimoto\n16:30-17:30 Jaehyun Hong \nOct. 20 \n10:00-11:00 Boris Kruglikov\n11:30-12:30 Mike Eastwood \nOrganizer\nJun-Muk Hwang (IBS-CCG) \nVenue\nB109\, IBS\, Daejeon\, Korea \nMore Information\n• How to get to IBS-CCG
URL:https://ccg.ibs.re.kr/event/2023-10-17-20/
LOCATION:B109\, IBS\, Korea\, Republic of
CATEGORIES:Conferences and Workshops
ATTACH;FMTTYPE=image/jpeg:https://ccg.ibs.re.kr/wp-content/uploads/2023/07/Workshop-on-parabolic-geometry-group-photo-scaled.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20231016T160000
DTEND;TZID=Asia/Seoul:20231016T170000
DTSTAMP:20260416T043940
CREATED:20231010T015627Z
LAST-MODIFIED:20231010T015627Z
UID:2584-1697472000-1697475600@ccg.ibs.re.kr
SUMMARY:Gil Bor\, Bicycle Tracks\, their Monodromy Invariants and Geodesics
DESCRIPTION:    Speaker\n\n\nGil Bor\nCIMAT\n\n\n\n\n\n\nAt first sight\, the pair of front and back wheel tracks left by a passing bike on a sandy or muddy terrain seems like a random pair of curves. This is not the case. For example\, one can usually distinguish between the front and back wheel tracks\, and even the direction at which these were traversed\, based solely on their shapes. You can try it for the following pair of paths. \n \nAnother example: If the front wheel traverses a small enough closed path (compared to the bike size)\, then\, typically\, the back track does not close up\, by an amount approximated by the area enclosed by the front track and the bicycle length; this fact was utilized to build a simple area measuring mechanical device\, now obsolete\, called the Hatchet planimeter. \nIn recent years the subject has attracted attention due to newly discovered relations with the theory of completely integrable systems (the filament flow)\, sub-Riemannian geometry and elasticity theory. I will try to describe some of these developments and open questions.
URL:https://ccg.ibs.re.kr/event/2023-10-16-1600-1700/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20231016T110000
DTEND;TZID=Asia/Seoul:20231016T120000
DTSTAMP:20260416T043940
CREATED:20231010T015222Z
LAST-MODIFIED:20231010T015241Z
UID:2580-1697454000-1697457600@ccg.ibs.re.kr
SUMMARY:Gil Bor\, Cusps of Caustics by Reflection in a Convex Billiard Table
DESCRIPTION:    Speaker\n\n\nGil Bor\nCIMAT\n\n\n\n\n\n\nPlace a point light source inside a smooth convex billiard table (or mirror). The n-th caustic by reflection is the envelope of light rays after n reflections. Theorem: each of these caustics\, for a generic point light source\, has at least 4 cusps. Conjecture: there are exactly 4 cusps iff the table is an ellipse. Here are the 2nd\, 5th and 8th caustics by reflection in an ellipse\, each with 4 cusps (marked by gray disks; the light source is the white disk) \n \nThis is a billiard version of “Jacobi’s Last Geometric Statement”\, concerning the number of cusps of the conjugate locus of a point on a convex surface\, proved so far only in the n=1 case. (Joint work with Serge Tabachnikov\, from Penn State\, USA).
URL:https://ccg.ibs.re.kr/event/2023-10-16-1100-1200/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20231010T110000
DTEND;TZID=Asia/Seoul:20231010T120000
DTSTAMP:20260416T043940
CREATED:20230924T041001Z
LAST-MODIFIED:20230924T041001Z
UID:2534-1696935600-1696939200@ccg.ibs.re.kr
SUMMARY:Guolei Zhong\, Positivity of Tangent Sheaf of Projective Varieties
DESCRIPTION:    Speaker\n\n\nGuolei Zhong\nIBS-CCG\n\n\n\n\n\n\nIn this talk\, we discuss the structure of projective varieties with certain positive tangent sheaves. More precisely\, when the tangent sheaf is almost nef or positively curved\, we construct a well-defined MRC fibration and study the Fujita decomposition of reflexive sheaves. Besides\, we show that the almost nefness of the tangent sheaf will impose rather restrictive condition on the singularities\, and some typical examples will be given. This is based on my recent joint work with Masataka Iwai and Shin-ichi Matsumura.
URL:https://ccg.ibs.re.kr/event/2023-10-10/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230921T150000
DTEND;TZID=Asia/Seoul:20230921T160000
DTSTAMP:20260416T043940
CREATED:20230905T122128Z
LAST-MODIFIED:20230905T122128Z
UID:2506-1695308400-1695312000@ccg.ibs.re.kr
SUMMARY:Yaoxiong Wen\, Generalized Quiver Mutation and PAX/PAXY Models
DESCRIPTION:    Speaker\n\n\nYaoxiong Wen\nKIAS\n\n\n\n\n\n\nDuring this presentation\, I will discuss the generalized quiver mutation conjecture proposed by Prof. Ruan. Our focus will be on proving this conjecture for the Grassmannian bundle. Additionally\, we will explore the determinantal variety and its two different desingularizations\, known as PAX/PAXY models. We will demonstrate the relationship between these models through generalized quiver mutation and prove the PAX/PAXY correspondence in the level of quasimap I-functions. This talk is based on the ongoing research collaboration with Mark Shoemaker and Nathan Priddis.
URL:https://ccg.ibs.re.kr/event/2023-09-21/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230919T110000
DTEND;TZID=Asia/Seoul:20230919T120000
DTSTAMP:20260416T043940
CREATED:20230909T045536Z
LAST-MODIFIED:20230909T045536Z
UID:2522-1695121200-1695124800@ccg.ibs.re.kr
SUMMARY:Seung uk Jang\, Vieta Involutions on Tropical Markov Cubics
DESCRIPTION:    Speaker\n\n\nSeung uk Jang\nUniversité de Rennes 1\n\n\n\n\n\n\nWe discuss the algebraic dynamics on Markov cubics generated by Vieta involutions\, in the tropicalized setting\, including some introduction to the tropicalization. It turns out that there is an invariant subset of the tropicalized Markov cubic where the action by Vieta involutions can be modeled by that of the Farey reflection group on the hyperbolic plane. \nSome applications in non-archimedean dynamics\, number theory\, or complex dynamical questions will also be introduced.
URL:https://ccg.ibs.re.kr/event/2023-09-19/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230908T110000
DTEND;TZID=Asia/Seoul:20230908T120000
DTSTAMP:20260416T043940
CREATED:20230731T073447Z
LAST-MODIFIED:20230904T004225Z
UID:2414-1694170800-1694174400@ccg.ibs.re.kr
SUMMARY:Fabrizio Catanese\, [IBS-KAIST Seminar] Geometry and Dynamics of Geometric Endomorphisms of the Hesse Moduli Space of Elliptic Curves
DESCRIPTION:    Speaker\n\n\nFabrizio Catanese\nUniversity of Bayreuth\n\n\n\n\n\n\nWe consider the geometric map C\, called Cayleyan\, associating to a plane cubic E the adjoint of its dual curve. We show that C and the classical Hessian map H generate a free semigroup. We begin the investigation of the geometry and dynamics of these maps\, and of the geometrically special elliptic curves: these are the elliptic curves isomorphic to cubics in the Hesse pencil which are fixed by some endomorphism belonging to the semigroup generated by H\, C. We point out how the dynamic behaviours of H and C differ drastically. Firstly\, concerning the number of real periodic points: for H these are infinitely many\, for C they are just 4. Secondly\, the Julia set of H is the whole projective line\, unlike what happens for all elements of the semigroup which are not iterates of H.
URL:https://ccg.ibs.re.kr/event/2023-09-08/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230907T150000
DTEND;TZID=Asia/Seoul:20230907T160000
DTSTAMP:20260416T043940
CREATED:20230731T073302Z
LAST-MODIFIED:20230731T084230Z
UID:2410-1694098800-1694102400@ccg.ibs.re.kr
SUMMARY:Yum-Tong Siu\, [IBS-KAIST Seminar] Differential Relations for Multiplier Ideal Sheaves in ∂ Estimates
DESCRIPTION:    Speaker\n\n\nYum-Tong Siu\nHarvard University\n\n\n\n\n\n\nFor sums of squares of real vector fields\, Hörmander linked subelliptic estimates to the spanning property of iterated Lie brackets of vector fields. Kohn studied the more complicated analogue of subelliptic ​∂​​​​ estimates for weakly pseudoconvex domains\, with vector-valued unknowns. \nIn the weak-solution approach to solving the ∂​​​ equation\, multipliers for the test function are introduced so that estimates hold after multiplication by a multiplier. Kohn used the dual formulation of differential forms instead of vector fields so that (i) the Lie brackets of vector fields are replaced by differential relations to generate new multipliers and (ii) the spanning property of iterated Lie brackets is replaced by the constant function 1 being a multiplier. \nWe will focus on recent problems and results concerning Kohn’s theory of subelliptic estimates in terms of D’Angelo’s condition of finite type. The distant eventual goal is to explore the theory for differential relations to generate multipliers for subelliptic estimates for a general system of equations with compatibility conditions.
URL:https://ccg.ibs.re.kr/event/2023-09-07-1500-1600/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230907T110000
DTEND;TZID=Asia/Seoul:20230907T120000
DTSTAMP:20260416T043940
CREATED:20230731T072556Z
LAST-MODIFIED:20230802T012652Z
UID:2408-1694084400-1694088000@ccg.ibs.re.kr
SUMMARY:Thomas Peternell\, Semipositive Tangent Bundles and Canonical Extensions
DESCRIPTION:    Speaker\n\n\nThomas Peternell\nUniversity of Bayreuth\n\n\n\n\n\n\nGiven a projective complex manifold M with an ample polarization there is canonically associated an affine bundle Z over M. The question I will discuss is under which circumstances Z is an affine variety\, or at least Stein. This is related to the global structure of M\, specifically to the semipositivity of the tangent bundle. I will explain the main conjectures and recent results (joint work with A. Höring).
URL:https://ccg.ibs.re.kr/event/2023-09-07-1100-1200/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230906T110000
DTEND;TZID=Asia/Seoul:20230906T120000
DTSTAMP:20260416T043940
CREATED:20230731T072411Z
LAST-MODIFIED:20230731T072411Z
UID:2406-1693998000-1694001600@ccg.ibs.re.kr
SUMMARY:George Hitching\, Brill-Noether Loci on Moduli Space of Symplectic Bundles over a Curve
DESCRIPTION:    Speaker\n\n\nGeorge Hitching\nOslo Metropolitan University\n\n\n\n\n\n\nLet C be a smooth projective curve of genus g. The symplectic Brill-Noether locus S(k\, 2n\, K) parametrises stable bundles of rank 2n over C with at least k independent sections\, and which admit a nondegenerate skewsymmetric bilinear form with values in the canonical bundle K. This is a symmetric determinantal variety whose tangent spaces are described by a symmetrised Petri map. We show for many values of g\, n and k that S(k\, 2n\, K) is nonempty and has a component which is generically smooth and of the expected dimension. As an application\, we show that for certain n and k\, for any curve of large genus the usual Brill-Noether locus B(k\, 2n\, 2n(g-1)) has a component of excess dimension. This is joint work with Ali Bajravani (Tabriz/Berlin).
URL:https://ccg.ibs.re.kr/event/2023-09-06/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230905T160000
DTEND;TZID=Asia/Seoul:20230905T170000
DTSTAMP:20260416T043940
CREATED:20230904T004640Z
LAST-MODIFIED:20230904T004709Z
UID:2498-1693929600-1693933200@ccg.ibs.re.kr
SUMMARY:Takayuki Koike\, On Some Variants of Ueda's Lemma and its Application
DESCRIPTION:    Speaker\n\n\nTakayuki Koike\n(Osaka Metropolitan University)\n\n\n\n\n\n\nIn this talk\, we explain our results on some variants of Ueda’s lemma on L∞-estimates for Cech coboundary operators that hold uniformly for all flat holomorphic line bundles on compact Kähler manifolds. This talk is partially based on joint work with Y. Hashimoto and T. Uehara.Title : Non-measure hyperbolicity of K3 and Enriques surfaces.
URL:https://ccg.ibs.re.kr/event/2023-09-05/
LOCATION:on-line
CATEGORIES:Several Complex Variables Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20230816
DTEND;VALUE=DATE:20230819
DTSTAMP:20260416T043940
CREATED:20230504T070002Z
LAST-MODIFIED:20230731T055006Z
UID:2280-1692144000-1692403199@ccg.ibs.re.kr
SUMMARY:KSCV Workshop #26
DESCRIPTION:Speakers\nTaeyong Ahn (Inha University)\nYe-Won Luke Cho (Pusan National University)\nYoung-Jun Choi (Pusan National University)\nPham Hoang Hiep (Vietnam Academy of Science and Technology)\nDinh Tuan Huynh (Hue University of Education-Hue University)\nŁukasz Kosiński (Jagiellonian University)\nKang-Hyurk Lee (Gyeongsang National University)\nMan-Chun Lee (The Chinese University of Hong Kong)\nHoseob Seo (Institute for Basic Science)\nGuolei Zhong (Institute for Basic Science) \nAbstracts\nPDF File \nSchedule\nDay 1: August 16 (Wednesday) \n\n\n\n~10:00\nRegistration\n\n\n10:00~11:00\nKang-Hyurk Lee\nThe method of potential rescaling and a characterization of the unit ball\n\n\n11:00~11:30\nCoffee Break\n\n\n11:30~12:30\nDinh Tuan Huynh (online)\nUniversal entrie curves in projective spaces with slow growth\n\n\n12:30~14:30\nLunch\n\n\n14:30~15:30\nTaeyong Ahn\nEquidistribution of positive closed currents on a compact Kähler manifold\n\n\n15:30~16:00\nCoffee Break\n\n\n16:00-17:00\nGuolei Zhong\nCompact Kähler threefolds with the action of an abelian group of maximal dynamical rank\n\n\n18:00~20:00\nSpeakers Dinner\n\n\n\n  \nDay 2: August 17 (Thursday) \n\n\n\n10:00~11:00\nYoung-Jun Choi\nAn injectivity theorem on snc compact Kähler spaces\n\n\n11:00~11:30\nCoffee Break\n\n\n11:30~12:30\nPham Hoang Hiep (online)\nSingularity invariants of plurisubharmonic functions\n\n\n12:30~14:30\nLunch\n\n\n14:30~15:30\nMan-Chun Lee\nKähler-Ricci flow on non-compact manifolds and application\n\n\n15:30~16:00\nCoffee Break\n\n\n16:00-17:00\nYe-Won Luke Cho\nContinuity of singular Kähler-Einstein potentials\n\n\n17:30-19:00\nBanquet\n\n\n\n  \nDay 3: August 19 (Friday) \n\n\n\n10:00~11:00\nHoseob-Seo\nOhsawa measures on singular hypersurfaces and its applications\n\n\n11:00~11:30\nCoffee Break\n\n\n11:30~12:30\nŁukasz Kosiński\nA Gehring-Hayman inequality\n\n\n\nOrganizers\nDano Kim (Seoul National University)\nSung-Yeon Kim (Institute for Basic Science)\nN. Cuong Nguyen (Korea Advanced Institute of Science and Technology)\nAeryeong Seo (Kyungpook National University) \nVenue\nB109\, IBS\, Korea \nRegistration\nPlease submit Google form by July 28. \nMore Information\n• How to get to IBS-CCG\n• From Hotel to IBS\n• IBS Cafeteria (Lunch) \nParticipants\nSui-Chung Ng (East China Normal University)\nBou Kang (KAIST)\nMario Chan (Pusan National University)\nJisoo Byun (Kyungnam University)\nHoseob Seo (Institute for Basic Science)\nSungmin Yoo (Incheon National University)\nSeungjae Lee (Institute for Basic Science)\nHan-Wool Lee (Korea University)\nHanjin Lee (Handong Global University)\nJiwon Jeong (Pusan National University)\nYe-Won Luke Cho (Pusan National University)\nBoo Rim Choe (Korea University)\nHyunil Choi (Pusan National University)\nJihun Yum (Institute for Basic Science)\nKang-Hyurk Lee (Gyeongsang National University)\nDo young Choi (KAIST)\nKang-Tae Kim (POSTECH)\nChiwon Yoon (KAIST) \nSupported by Institute for Mathematical Convergence\, KNU
URL:https://ccg.ibs.re.kr/event/2023-08-16-18/
LOCATION:B109\, IBS\, Korea\, Republic of
CATEGORIES:Conferences and Workshops
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230808T150000
DTEND;TZID=Asia/Seoul:20230808T163000
DTSTAMP:20260416T043940
CREATED:20230720T004618Z
LAST-MODIFIED:20230720T004618Z
UID:2377-1691506800-1691512200@ccg.ibs.re.kr
SUMMARY:Kyeong-Dong Park\, K-stability of Fano Spherical Varieties\, III
DESCRIPTION:    Speaker\n\n\nKyeong-Dong Park\nGyeongsang National University\n\n\n\n\n\n\nThe aim of this seminar is to provide participants with a comprehensive understanding of the paper “K-stability of Fano spherical varieties” by Thibaut Delcroix. For a reductive algebraic group G\, a normal G-variety is called spherical if it contains an open B-orbit\, where B is a fixed Borel subgroup of G. The class of spherical varieties contains several important families which were studied independently\, for example\, toric varieties\, rational homogeneous varieties\, group embeddings\, horospherical varieties\, symmetric varieties\, and wonderful varieties. They are classified by combinatorial objects called colored fans\, which generalize the fans appearing in the classification of toric varieties. We discuss Delcroix’s combinatorial criterion for K-stability of a smooth Fano spherical variety in terms of the barycenter of its moment polytope with respect to the Duistermaat-Heckman measure and data associated to the corresponding spherical homogeneous space. \n(1) Spherical varieties\, colored fans\, and algebraic moment polytopes \n(2) Criterion for K-stability of Fano spherical varieties and its applications \n(3) Equivariant test configurations with horospherical central fiber\, and modified Futaki invariant
URL:https://ccg.ibs.re.kr/event/2023-08-08-1500-1630/
LOCATION:B266\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230808T103000
DTEND;TZID=Asia/Seoul:20230808T120000
DTSTAMP:20260416T043940
CREATED:20230720T004506Z
LAST-MODIFIED:20230720T004633Z
UID:2375-1691490600-1691496000@ccg.ibs.re.kr
SUMMARY:Kyeong-Dong Park\, K-stability of Fano Spherical Varieties\, II
DESCRIPTION:    Speaker\n\n\nKyeong-Dong Park\nGyeongsang National University\n\n\n\n\n\n\nThe aim of this seminar is to provide participants with a comprehensive understanding of the paper “K-stability of Fano spherical varieties” by Thibaut Delcroix. For a reductive algebraic group G\, a normal G-variety is called spherical if it contains an open B-orbit\, where B is a fixed Borel subgroup of G. The class of spherical varieties contains several important families which were studied independently\, for example\, toric varieties\, rational homogeneous varieties\, group embeddings\, horospherical varieties\, symmetric varieties\, and wonderful varieties. They are classified by combinatorial objects called colored fans\, which generalize the fans appearing in the classification of toric varieties. We discuss Delcroix’s combinatorial criterion for K-stability of a smooth Fano spherical variety in terms of the barycenter of its moment polytope with respect to the Duistermaat-Heckman measure and data associated to the corresponding spherical homogeneous space. \n(1) Spherical varieties\, colored fans\, and algebraic moment polytopes \n(2) Criterion for K-stability of Fano spherical varieties and its applications \n(3) Equivariant test configurations with horospherical central fiber\, and modified Futaki invariant
URL:https://ccg.ibs.re.kr/event/2023-08-08-1030-1200/
LOCATION:B266\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230807T150000
DTEND;TZID=Asia/Seoul:20230807T163000
DTSTAMP:20260416T043940
CREATED:20230720T004336Z
LAST-MODIFIED:20230802T043609Z
UID:2372-1691420400-1691425800@ccg.ibs.re.kr
SUMMARY:Kyeong-Dong Park\, K-stability of Fano Spherical Varieties\, I
DESCRIPTION:    Speaker\n\n\nKyeong-Dong Park\nGyeongsang National University\n\n\n\n\n\n\nThe aim of this seminar is to provide participants with a comprehensive understanding of the paper “K-stability of Fano spherical varieties” by Thibaut Delcroix. For a reductive algebraic group G\, a normal G-variety is called spherical if it contains an open B-orbit\, where B is a fixed Borel subgroup of G. The class of spherical varieties contains several important families which were studied independently\, for example\, toric varieties\, rational homogeneous varieties\, group embeddings\, horospherical varieties\, symmetric varieties\, and wonderful varieties. They are classified by combinatorial objects called colored fans\, which generalize the fans appearing in the classification of toric varieties. We discuss Delcroix’s combinatorial criterion for K-stability of a smooth Fano spherical variety in terms of the barycenter of its moment polytope with respect to the Duistermaat-Heckman measure and data associated to the corresponding spherical homogeneous space. \n(1) Spherical varieties\, colored fans\, and algebraic moment polytopes \n(2) Criterion for K-stability of Fano spherical varieties and its applications \n(3) Equivariant test configurations with horospherical central fiber\, and modified Futaki invariant
URL:https://ccg.ibs.re.kr/event/2023-08-07-1500-1630/
LOCATION:B266\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230807T140000
DTEND;TZID=Asia/Seoul:20230807T145000
DTSTAMP:20260416T043940
CREATED:20230802T061117Z
LAST-MODIFIED:20230802T061320Z
UID:2425-1691416800-1691419800@ccg.ibs.re.kr
SUMMARY:Minseong Kwon\, Spherical Geometry of Hilbert Schemes of Conics in Adjoint Varieties
DESCRIPTION:    Speaker\n\n\nMinseong Kwon\nKAIST\n\n\n\n\n\n\nFor each rational homogeneous space\, the space of lines is now well-understood and can be described in terms of the induced group action. It is natural to consider rational curves of higher degree\, and in this talk\, we discuss geometry of conics in adjoint varieties\, which are rational homogeneous spaces associated to simple Lie algebras. Each adjoint variety is equipped with a hyperplane distribution called the contact distribution\, and we show that smooth conics transverse to the contact distribution form a homogeneous symmetric variety if the adjoint variety is of Picard number 1. This enables us to view the Hilbert scheme of conics as a spherical variety\, and we compute its colored fan by using the description of the space of lines and the Hilbert-Chow morphism.
URL:https://ccg.ibs.re.kr/event/2023-08-07-1400-1450/
LOCATION:B266\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230803T160000
DTEND;TZID=Asia/Seoul:20230803T170000
DTSTAMP:20260416T043940
CREATED:20230724T090504Z
LAST-MODIFIED:20230724T090504Z
UID:2389-1691078400-1691082000@ccg.ibs.re.kr
SUMMARY:Gunhee Cho\, Non-measure Hyperbolicity of K3 and Enriques Surfaces
DESCRIPTION:    Speaker\n\n\nGunhee Cho\nUCSB\n\n\n\n\n\n\nBy exploiting the upper semicontinuity of the Kobayashi-Eisenman pseudo volume (and pseudometric) under deformations of complex structures\, we establish the non-measure hyperbolicity of K3 surfaces—which M. Green and P. Griffiths verified for certain cases in 1980—holds for all K3 surfaces. Our result provides a stronger condition than the Kobayashi non-hyperbolicity for any complex K3 surface\, which had been demonstrated by L. Kamenova\, S. Lu\, and M. Verbitsky. An interesting consequence is the non-measure hyperbolicity of Enriques surfaces. This is the joint work with David R. Morrison.
URL:https://ccg.ibs.re.kr/event/2023-08-03/
LOCATION:B266\, IBS\, Korea\, Republic of
CATEGORIES:Several Complex Variables Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230726T100000
DTEND;TZID=Asia/Seoul:20230726T121500
DTSTAMP:20260416T043940
CREATED:20230615T085501Z
LAST-MODIFIED:20230615T085501Z
UID:2321-1690365600-1690373700@ccg.ibs.re.kr
SUMMARY:Chang-Yeon Chough\, Introduction to algebraic stacks\, VII\, VIII
DESCRIPTION:    Speaker\n\n\nChang-Yeon Chough\nSogang Univ.\n\n\n\n\n\n\nThis is an 8 hours long lecture series on algebraic stacks\, which have become an important part of algebraic geometry (for example\, in the study of moduli spaces) since Deligne and Mumford established the foundation of the theory of stacks. This crash course will be following roughly “Algebraic Spaces and Stacks” by Martin Olsson. Our main goal is to set up a foundation for the theory of algebraic stacks\, so that the attendees would be able to use it in their own research in the future.
URL:https://ccg.ibs.re.kr/event/2023-07-26/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230725T150000
DTEND;TZID=Asia/Seoul:20230725T173000
DTSTAMP:20260416T043940
CREATED:20230615T085406Z
LAST-MODIFIED:20230712T131050Z
UID:2319-1690297200-1690306200@ccg.ibs.re.kr
SUMMARY:Chang-Yeon Chough\, Introduction to algebraic stacks\, V\, VI
DESCRIPTION:    Speaker\n\n\nChang-Yeon Chough\nSogang Univ.\n\n\n\n\n\n\nThis is an 8 hours long lecture series on algebraic stacks\, which have become an important part of algebraic geometry (for example\, in the study of moduli spaces) since Deligne and Mumford established the foundation of the theory of stacks. This crash course will be following roughly “Algebraic Spaces and Stacks” by Martin Olsson. Our main goal is to set up a foundation for the theory of algebraic stacks\, so that the attendees would be able to use it in their own research in the future.
URL:https://ccg.ibs.re.kr/event/2023-07-25-1500-1730/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230725T110000
DTEND;TZID=Asia/Seoul:20230725T120000
DTSTAMP:20260416T043940
CREATED:20230712T131020Z
LAST-MODIFIED:20230716T052748Z
UID:2356-1690282800-1690286400@ccg.ibs.re.kr
SUMMARY:Patrick Brosnan\, How Markman Saves the Hodge Conjecture (for Weil Type Abelian Fourfolds) from Kontsevich\, II
DESCRIPTION:    Speaker\n\n\nPatrick Brosnan\nUniversity of Maryland\n\n\n\n\n\n\nI’ll explain what I know about two very interesting pieces of work: \n(1) Markman’s proof of the Hodge conjecture for Weil type abelian fourfolds of discriminant 1. \n(2) Kontsevich’s tropical approach to looking for counterexamples to the Hodge conjecture for Weil type abelian varieties. \nThen I’ll explain a simple observation of mine\, which implies that Kontsevich’s approach cannot work for abelian fourfolds of any discriminant. \nI’ll start out by explaining the statement of (1) precisely along with the geometric input that is required in (2). Then I’ll formulate my observation\, which is really about why the discriminant determines what types of degenerations an abelian fourfold of Weil type can have. Along the way\, I’ll take the opportunity to say a little bit about Markman’s proof of (1).
URL:https://ccg.ibs.re.kr/event/2023-07-25-1100-1200/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230720T110000
DTEND;TZID=Asia/Seoul:20230720T120000
DTSTAMP:20260416T043940
CREATED:20230712T130908Z
LAST-MODIFIED:20230716T052735Z
UID:2354-1689850800-1689854400@ccg.ibs.re.kr
SUMMARY:Patrick Brosnan\, How Markman Saves the Hodge Conjecture (for Weil Type Abelian Fourfolds) from Kontsevich\, I
DESCRIPTION:    Speaker\n\n\nPatrick Brosnan\nUniversity of Maryland\n\n\n\n\n\n\nI’ll explain what I know about two very interesting pieces of work: \n(1) Markman’s proof of the Hodge conjecture for Weil type abelian fourfolds of discriminant 1. \n(2) Kontsevich’s tropical approach to looking for counterexamples to the Hodge conjecture for Weil type abelian varieties. \nThen I’ll explain a simple observation of mine\, which implies that Kontsevich’s approach cannot work for abelian fourfolds of any discriminant. \nI’ll start out by explaining the statement of (1) precisely along with the geometric input that is required in (2). Then I’ll formulate my observation\, which is really about why the discriminant determines what types of degenerations an abelian fourfold of Weil type can have. Along the way\, I’ll take the opportunity to say a little bit about Markman’s proof of (1).
URL:https://ccg.ibs.re.kr/event/2023-07-20/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230719T100000
DTEND;TZID=Asia/Seoul:20230719T121500
DTSTAMP:20260416T043940
CREATED:20230615T085304Z
LAST-MODIFIED:20230615T085519Z
UID:2317-1689760800-1689768900@ccg.ibs.re.kr
SUMMARY:Chang-Yeon Chough\, Introduction to algebraic stacks\, III\, IV
DESCRIPTION:    Speaker\n\n\nChang-Yeon Chough\nSogang Univ.\n\n\n\n\n\n\nThis is an 8 hours long lecture series on algebraic stacks\, which have become an important part of algebraic geometry (for example\, in the study of moduli spaces) since Deligne and Mumford established the foundation of the theory of stacks. This crash course will be following roughly “Algebraic Spaces and Stacks” by Martin Olsson. Our main goal is to set up a foundation for the theory of algebraic stacks\, so that the attendees would be able to use it in their own research in the future.
URL:https://ccg.ibs.re.kr/event/2023-07-19/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20230718T150000
DTEND;TZID=Asia/Seoul:20230718T173000
DTSTAMP:20260416T043940
CREATED:20230615T085143Z
LAST-MODIFIED:20230615T085546Z
UID:2315-1689692400-1689701400@ccg.ibs.re.kr
SUMMARY:Chang-Yeon Chough\, Introduction to algebraic stacks\, I\, II
DESCRIPTION:    Speaker\n\n\nChang-Yeon Chough\nSogang Univ.\n\n\n\n\n\n\nThis is an 8 hours long lecture series on algebraic stacks\, which have become an important part of algebraic geometry (for example\, in the study of moduli spaces) since Deligne and Mumford established the foundation of the theory of stacks. This crash course will be following roughly “Algebraic Spaces and Stacks” by Martin Olsson. Our main goal is to set up a foundation for the theory of algebraic stacks\, so that the attendees would be able to use it in their own research in the future.
URL:https://ccg.ibs.re.kr/event/2023-07-18/
LOCATION:B236-1\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
END:VCALENDAR