[geometry-ml:06921] 大阪大学幾何セミナー(7月6日)

[Masataka Iwai]

皆様

大阪大学の岩井雅崇です. 大阪大学幾何セミナーのご案内をいたします.

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日時:
2026年7月6日(月) 13:30--15:00

場所:
大阪大学理学部E404講義室(豊中キャンパス)

講演者:
小池 貴之 (筑波大学)

タイトル:
Pluripotential geometry on semi-positive effective divisors of
numerical dimension one

アブストラクト:
We study the complex-analytic geometry of semi-positive holomorphic
line bundles on compact Kähler manifolds. In one of our main results,
for a Q-effective line bundle satisfying a natural torsion-type
assumption, we show the equivalence between semi-positivity and
semi-ampleness. More generally, for an effective nef divisor of
numerical dimension one, we characterize the semi-positivity of the
associated line bundle in terms of the existence of a certain type of
pseudoflat fundamental system of neighborhoods of the support.
Furthermore, for an effective semi-positive divisor, we prove a
dichotomy: either the divisor is the pull-back of a Q-divisor by a
fibration onto a Riemann surface, or the Hartogs extension phenomenon
holds on the complement of its support. Our proof is based on a
pluripotential method that has previously been used for studying the
boundaries of pseudoconvex domains, which allows us to investigate the
complex-analytic structure of neighborhoods of the support of the
divisor even when the manifold is non-compact.
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今後のセミナー予定表: http://www4.math.sci.osaka-u.ac.jp/sembbs2/announce.cgi
皆様のご参加をお待ちしております.

世話人：岩井雅崇, 田代賢志郎, 松本佳彦（順不同）

大阪大学大学院理学研究科数学専攻
岩井雅崇
住所: 560-0043　大阪府豊中市待兼山町１-１
メールアドレス: masataka ＠ math.sci.osaka-u.ac.jp, masataka.math ＠ gmail.com,
iwai.masataka.sci ＠ osaka-u.ac.jp