Differential Geometry Seminar (2018)

As a project of OCAMI, we shall promote the seminar on differential geometry in the wide sense of including the areas related to geometric analysis, topology, algebraic geometry, mathematical physics, integrable systems, information sciences etc.

Contact Yoshihiro Ohnita
Hiroshi Tamaru
Shin Kato
Kaname Hashimoto
Masashi Yasumoto
Department of Mathematics Osaka City University
Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, JAPAN
TEL 06-6605-2617 (Ohnita)
06-6605-2616 (Kato)
E-mail ohnita[at]sci.osaka-cu.ac.jp
tamaru[at]sci.osaka-cu.ac.jp
shinkato[at]sci.osaka-cu.ac.jp
h-kaname[at]sci.osaka-cu.ac.jp
yasumoto[at]sci.osaka-cu.ac.jp
Speaker Osamu Kobayashi (OCAMI)
Title 定傾曲線定理の一般化
Date March 8 (Fri.) 14:45 ~ 16:15
Place Dept. of Mathematics, Sci. Bldg., F405
Abstract Japanese page only
Speaker Shin-ichi Matsumura (Tohoku University)
Title On projective manifolds with semi-positive holomorphic sectional curvature
Date January 1 (Tue.) 16:00 ~ 17:30
Place Dept. of Mathematics, Sci. Bldg., E408
Abstract In this talk, I explain the geometry of a projective manifold (more generally a Kaehler manifold) X with semi-positive holomorphic sectional curvature. I first show that, if X has positive holomorphic sectional curvature, then X is rationally connected, that is, arbitrary two points can be connected by a rational curve (the image of P^1 by a holomorphic map). This result gives an affirmative solution for Yau's conjecture. Moreover I show that, if X has semi-positive holomorphic sectional curvature, X admits a locally trivial morphism from X to Y such that the fiber F is rationally connected and the image Y has a finite etale cover by an abelian variety A. This structure theorem can be seen as a generalization of the structure theorem proved by Howard-Smyth-Wu and Mok for holomorphic "bisectional" curvature. Also I show that the universal cover of X is biholomorphic and isometric to the product of C^m and F. The proof depends on the theory of holomorphic foliations. MRC fibrations, and singular hermitian metrics.
Speaker Yu Wang (SUSE/OCAMI)
Title Geodesic orbit metrics in compact homogeneous manifolds with equivalent isotropy summands
Date November 21 (Wed.) 2018, 14:45 ~ 16:15
Place Dept. of Mathematics, Sci. Bldg., E408
Abstract pdf file
Last Modified on 2019. 3. 8