令和8年度前期講演

日時 4月17日(金) 16:00--18:15
会場 西新プラザ 2階 中会議室

講師/講演時間 津原 駿 氏(大阪大学)/ 16:00--17:00
題目 Scattering problem for the Schrödinger equation with a nonlinear boundary condition
概要 ゲージ不変な非線形境界項を伴う半空間上の非線形Schrödinger方程式を考察する. 方程式に内在する保存則を考慮すると, \(L^2\)を基調とするSobolev空間での適切性ならびに解の散乱が自然に期待される. 本発表ではまず, Strichartz評価に基づく適切性の結果について概観する. 特に, 境界項から現れる振動積分に着目し, Strichartz評価が成立するLebesgue指数の制限について述べる. さらに非線形項の係数が反発的である場合に, 解が散乱する非線形項の臨界指数として半空間特有の指数が現れることを述べる.

講師/講演時間 赤木 剛朗 氏(東北大学)/ 17:15--18:15
題目 Optimal rate of convergence to degenerate asymptotic profiles for fast diffusion in thin annuli
概要 In this talk, we discuss the optimal rate of convergence to asymptotic profiles of solutions, which vanish in finite time, to the Fast Diffusion Equation posed on bounded domains. Quantitative studies in this direction have developed significantly since the celebrated work of Bonforte and Figalli (2021). However, in most existing results, asymptotic profiles are assumed to be nondegenerate, meaning that the linearized operator has a trivial kernel. In fact, such nondegeneracy holds for generic domains. On the other hand, it is well known that least-energy solutions to the Emden-Fowler equation in thin annuli are nonradial. As a consequence, they are degenerate and thus fall outside the scope of previous works. In this talk, inspired by recent work of König and Yu (2024+), we establish the optimal convergence rate to such degenerate asymptotic profiles for certain space dimensions. This talk is based on a recent joint work with Norihisa Ikoma (Keio University) and Yasunori Maekawa (Kyoto University).



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