東京無限可積分系セミナー

過去の記録 ~03/28次回の予定今後の予定 03/29~

開催情報 土曜日 13:30~16:00 数理科学研究科棟(駒場) 117号室
担当者 神保道夫、国場敦夫、山田裕二、武部尚志、高木太一郎、白石潤一
セミナーURL https://www.ms.u-tokyo.ac.jp/~takebe/iat/index-j.html

2008年02月23日(土)

13:00-16:30   数理科学研究科棟(駒場) 270号室
岩尾慎介 氏 (東大数理) 13:00-14:30
Solutions of hungry periodic discrete Toda equation and its ultradiscretization
[ 講演概要 ]
The hungry discrete Toda equation is a generalization of the discrete Toda
equation. Through the method of ultradiscretization, the generalized
Box-ball system (gBBS) with finitely many kinds of balls is obtained from
hungry discrete Toda eq.. It is to be expected that the general solution of
gBBS should be obtained from the solution of hungry discrete Toda eq.
through ultradiscretization. In this talk, we derive the solutions of hungry
periodic discrete Toda eq. (hpd Toda eq.), by using inverse scattering
method. Although the hpd Toda equation does not linearlized in the usual
sense on the Picard group of the spectral curve, it is possible to determine
its behavior on the Picard group.
竹縄知之 氏 (東京海洋大・海洋工) 15:00-16:30
A tropical analogue of Fay's trisecant identity and its application to the ultra-discrete periodic Toda equation.
[ 講演概要 ]
The ultra-discrete Toda equation is essentially equivalent to the integrable
Box and Ball system, and considered to be a fundamental object in
ultra-discrete integrable systems. In this talk, we construct the general
solution of ultra-discrete Toda equation with periodic boundary condition,
by using the tropical theta function and the bilinear form. The tropical
theta function is associated with the tropical curve defined through the Lax
matrix of (not ultra-) discrete periodic Toda equation. For the proof, we
introduce a tropical analogue of Fay's trisecant identity. (This talk is
based on the joint work with R. Inoue.)