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Lie群論・表現論セミナー

過去の記録 ~06/28次回の予定今後の予定 06/29~

開催情報 火曜日 16:30~18:00 数理科学研究科棟(駒場) 126号室
担当者 小林俊行
セミナーURL https://www.ms.u-tokyo.ac.jp/~toshi/seminar/ut-seminar.html

2015年01月27日(火)

16:30-18:00   数理科学研究科棟(駒場) 126号室
大矢浩徳 氏 (東京大学大学院数理科学研究科)
Representations of quantized function algebras and the transition matrices from Canonical bases to PBW bases (JAPANESE)
[ 講演概要 ]
Let G be a connected simply connected simple complex algebraic group of type ADE and g the corresponding simple Lie algebra. In this talk, I will explain our new algebraic proof of the positivity of the transition matrices from the canonical basis to the PBW bases of Uq(n+). Here, Uq(n+) denotes the positive part of the quantized enveloping algebra Uq(g). (This positivity, which is a generalization of Lusztig's result, was originally proved by Kato (Duke Math. J. 163 (2014)).) We use the relation between Uq(n+) and the specific irreducible representations of the quantized function algebra Qq[G]. This relation has recently been pointed out by Kuniba, Okado and Yamada (SIGMA. 9 (2013)). Firstly, we study it taking into account the right Uq(g)-algebra structure of Qq[G]. Next, we calculate the transition matrices from the canonical basis to the PBW bases using the result obtained in the first step.