BEGIN:VCALENDAR
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PRODID:-//Center for Complex Geometry - ECPv6.16.3//NONSGML v1.0//EN
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X-ORIGINAL-URL:https://ccg.ibs.re.kr
X-WR-CALDESC:Events for Center for Complex Geometry
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X-Robots-Tag:noindex
X-PUBLISHED-TTL:PT1H
BEGIN:VTIMEZONE
TZID:Asia/Seoul
BEGIN:STANDARD
TZOFFSETFROM:+0900
TZOFFSETTO:+0900
TZNAME:KST
DTSTART:20210101T000000
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BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20220302T160000
DTEND;TZID=Asia/Seoul:20220302T170000
DTSTAMP:20260614T235418
CREATED:20220302T070000Z
LAST-MODIFIED:20220216T081710Z
UID:1122-1646236800-1646240400@ccg.ibs.re.kr
SUMMARY:Duc-Viet Vu\, Moser-Trudinger Inequalities and Complex Monge-Ampere Equations
DESCRIPTION:     Speaker\n\n\nDuc-Viet Vu\nCologne\n\n\n\n\n\nI present a version of the Moser-Trudinger inequality in the setting of complex geometry. As a very particular case\, the result already gives a new Moser-Trudinger inequality for functions in the Sobolev space W1\,2 of a domain in R2. As an application\, we deduce a new necessary condition for the complex Monge-Ampere equation for a given measure on a compact Kahler manifold to admit a Holder continuous solution. This is a joint work with Tien-Cuong Dinh and George Marinescu.
URL:https://ccg.ibs.re.kr/event/2022-03-02/
LOCATION:on-line
CATEGORIES:Several Complex Variables Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20220303T150000
DTEND;TZID=Asia/Seoul:20220303T160000
DTSTAMP:20260614T235418
CREATED:20220303T060000Z
LAST-MODIFIED:20220214T022608Z
UID:1110-1646319600-1646323200@ccg.ibs.re.kr
SUMMARY:Luca Rizzi\, An Approach to the Fujita Decomposition via Massey Products and Castelnuovo-de Franchis Theorem
DESCRIPTION:     Speaker\n\n\nLuca Rizzi\nIBS CCG\n\n\n\n\n\nLet f be a semistable fibration between a smooth complex variety of dimension n and a smooth complex curve. By a famous result of Fujita the direct image of the relative dualizing sheaf is the direct sum of a unitary flat vector bundle and an ample vector bundle. In this talk we focus our attention on the former: unitary flat bundles are in one-to-one correspondence with local systems and monodromy representations and I will show how these local systems are related to the de Rham closed one forms and top forms on the fibers of f. I will also give an introduction on the construction of Massey products and show its close relation with both a famous result by Castelnuovo and de Franchis and these local systems. Thanks to the presented techniques it is possible to give some results on the finiteness of the monodromy associated to the unitary flat bundle; equivalently on its semi-ampleness.
URL:https://ccg.ibs.re.kr/event/2022-03-03-1500/
LOCATION:TBA
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20220303T162000
DTEND;TZID=Asia/Seoul:20220303T172000
DTSTAMP:20260614T235418
CREATED:20220207T112309Z
LAST-MODIFIED:20220207T112309Z
UID:1112-1646324400-1646328000@ccg.ibs.re.kr
SUMMARY:Guolei Zhong\, Strictly Nef Divisors on Singular Varieties
DESCRIPTION:     Speaker\n\n\nGuolei Zhong\nIBS CCG\n\n\n\n\n\nA Q-Cartier divisor on a normal projective variety is said to be strictly nef\, if it has positive intersection with every integral curve. It has been a long history for people to measure how far a strictly nef divisor is from being ample. In this talk\, I will survey some recent progress on this topic\, especially the generalizations of Campana-Peternell’s conjecture and Serrano’s conjecture. My talk is based on some joint works with Jie Liu\, Wenhao Ou\, Juanyong Wang and Xiaokui Yang.
URL:https://ccg.ibs.re.kr/event/2022-03-03-1620/
LOCATION:TBA
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20220308T110000
DTEND;TZID=Asia/Seoul:20220308T120000
DTSTAMP:20260614T235418
CREATED:20220308T020000Z
LAST-MODIFIED:20220222T011638Z
UID:977-1646737200-1646740800@ccg.ibs.re.kr
SUMMARY:Atsushi Ito\, Projective Normality of General Polarized Abelian Varieties
DESCRIPTION:     Speaker\n\n\nAtsushi Ito\nOkayama Univ.\n\n\n\n\n\nProjective normality is an important property of ample line bundles on algebraic varieties.\nIn this talk\, I will explain that a general g-dimensional polarized abelian variety is projectively normal if χ(X\, L) > 22g-1.\nWe note that this bound is sharp. A key tool is basepoint-freeness threshold\, which is introduced by Jiang-Pareschi recently.
URL:https://ccg.ibs.re.kr/event/2022-03-08/
LOCATION:on-line
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20220324T150000
DTEND;TZID=Asia/Seoul:20220324T160000
DTSTAMP:20260614T235418
CREATED:20220324T060000Z
LAST-MODIFIED:20220314T062449Z
UID:1200-1648134000-1648137600@ccg.ibs.re.kr
SUMMARY:Yonghwa Cho\, Nodal Sextics and Even Sets of Nodes
DESCRIPTION:     Speaker\n\n\nYonghwa Cho\nIBS CCG\n\n\n\n\n\nIt is a classical question to ask how many nodes may a surface contain. For sextics\, the maximum number of nodes is 65\, and is attained by Barth’s example. We ask further: are all sextics with 65 nodes like Barth’s example? To find an answer\, we study even sets of nodes on sextic surfaces\, and prove that all sextics with 65 nodes share the same structure of even sets. This establishes a resemblance between Barth’s sextic and other sextics with 65 nodes. This talk is based on a joint work with Fabrizio Catanese\, Michael Kiermaier\, and Sascha Kurz.
URL:https://ccg.ibs.re.kr/event/2022-03-24-1500/
LOCATION:B234
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20220324T162000
DTEND;TZID=Asia/Seoul:20220324T172000
DTSTAMP:20260614T235418
CREATED:20220304T075827Z
LAST-MODIFIED:20220304T075827Z
UID:1197-1648138800-1648142400@ccg.ibs.re.kr
SUMMARY:Hoseob Seo\, On L2 Extension from Singular Hypersurfaces
DESCRIPTION:     Speaker\n\n\nHoseob Seo\nIBS CCG\n\n\n\n\n\nIn L2 extension theorems from an irreducible singular hypersurface in a complex manifold\, important roles are played by certain measures such as the Ohsawa measure\, which determines when a given function can be extended. In this talk\, we show that the singularity of the Ohsawa measure can be identified in terms of algebraic geometry.\nUsing this\, we give an analytic proof of the inversion of adjunction in this setting. These considerations enable us to compare various positive and negative results on L2 extension from singular hypersurfaces. In particular\, we generalize a recent negative result of Guan and Li which places limitations on strengthening such L2 extension by employing a less singular measure in the place of the Ohsawa measure. This is joint work with Dano Kim.
URL:https://ccg.ibs.re.kr/event/2022-03-24-1620/
LOCATION:B234
CATEGORIES:Complex Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20220329T153000
DTEND;TZID=Asia/Seoul:20220329T163000
DTSTAMP:20260614T235418
CREATED:20220329T063000Z
LAST-MODIFIED:20220314T072452Z
UID:1094-1648567800-1648571400@ccg.ibs.re.kr
SUMMARY:Dongsoo Shin\, Deformations of Sandwiched Surface Singularities and the Semistable Minimal Model Program
DESCRIPTION:     Speaker\n\n\nDongsoo Shin\nChungnam National Univ.\n\n\n\n\n\nA sandwiched surface singularity is a rational surface singularity that admits a birational map to the complex projective plane. de Jong and van Straten [Duke Math J 1998] prove that deformations of sandwiched surface singularities are induced from special deformations of germs of plane curve singularities (called picture deformations). On the other hand\, Kollár and Shepherd-Barron [Invent Math 1988] conjecture that deformations of any rational surface singularities are described by special partial modifications (called P-modifications). So there are two different descriptions of deformations of sandwiched surface singularities. We provide a way to find a correspondence between picture deformations and P-resolutions (roughly speaking\, normal P-modifications with mild singularities) using the semistable minimal model program for complex 3-folds. As applications\, 1. we provide correspondence between various deformation theories of cyclic quotient surface singularities 2. We give proofs of Kollár conjecture for certain weighted homogeneous surface singularities.
URL:https://ccg.ibs.re.kr/event/2022-03-29-1530/
LOCATION:B266\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20220329T164500
DTEND;TZID=Asia/Seoul:20220329T174500
DTSTAMP:20260614T235418
CREATED:20220329T074500Z
LAST-MODIFIED:20220314T072557Z
UID:1096-1648572300-1648575900@ccg.ibs.re.kr
SUMMARY:Nam-Hoon Lee\, Mirror Pairs of Calabi-Yau Threefolds from Mirror Pairs of Quasi-Fano Threefolds
DESCRIPTION:     Speaker\n\n\nNam-Hoon Lee\nHongik Univ.\n\n\n\n\n\nWe present a new construction of mirror pairs of Calabi-Yau manifolds by smoothing normal crossing varieties\, consisting of two quasi-Fano manifolds. We introduce a notion of mirror pairs of quasi-Fano manifolds with anticanonical Calabi-Yau fibrations using conjectures about Landau-Ginzburg models. Utilizing this notion\, we give pairs of normal crossing varieties and show that the pairs of smoothed Calabi-Yau manifolds satisfy the Hodge number relations of mirror symmetry. We consider quasi-Fano threefolds that are some blow-ups of Gorenstein toric Fano threefolds and build 6518 mirror pairs of Calabi-Yau threefolds\, including 79 self-mirrors.
URL:https://ccg.ibs.re.kr/event/2022-03-29-1645/
LOCATION:B266\, IBS\, Korea\, Republic of
CATEGORIES:Algebraic Geometry Seminar
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