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Seminar on Geometric Complex Analysis

Seminar information archive ~06/21Next seminarFuture seminars 06/22~

Date, time & place Monday 10:30 - 12:00 128Room #128 (Graduate School of Math. Sci. Bldg.)
Organizer(s) Kengo Hirachi, Shigeharu Takayama

2023/04/24

10:30-12:00   Room #128 (Graduate School of Math. Sci. Bldg.)
On site+Zoom
Takeo Ohsawa (Nogoya Universiry)
Guan's theorems on optimal strong openness and concavity of minimal L2 integrals (日本語)
[ Abstract ]
Motivated by a question of approximating plurisubharmonic (=psh) functions by those with tame singularities, Demailly and Kollar asked several basic questions on the singularities of psh functions. Guan solved two of them effectively in a paper published in 2019. One of their corollaries says the following.

THEOREM. Let Ω be a pseudoconvex domain in Cn and let φ be a negative psh function on Ω such that Ωeφ<. Then, epφL1loc around x for any xΩ and p>1 satisfying the inequality pp1>ΩeφKΩ(x), where KΩ denotes the diagonalized Bergman kernel of Ω.

This remarkable result is a consequence of a basic property of the minimal L2 integrals (=MLI). The main purpose of the talk is to give an outline of the proof of Theorem by explaining the relation between several notions including the MLI which measure the singularities of psh functions. It will also be mentioned that the proof of Theorem is essentially based on the optimal Ohsawa-Takegoshi type extension theorem, which leads to a concavity property of MLI. Recent papers by Guan and his students will be reviewed, too.
[ Reference URL ]
https://u-tokyo-ac-jp.zoom.us/meeting/register/tZEqceqsrTIjEtRxenSMdPogvCxlWzAogj5A