新着情報

日　　時：　１月１６日（木）１５時３０分～１７時００分
（曜日が通常と異なりますので，ご注意ください．）

講 演 者：　Victor Isakov 氏 （Wichita State University)

題　　目：　On increasing stability in the Cauchy and inverse problems for the
Helmholtz type elliptic equations

要　　旨：　We derive conditional stability estimates for the Helmholtz type equations
which are becoming of Lipschitz type for large frequencies/wave numbers.
Proofs use splitting solutions into low and high frequencies parts where we use energy
(in particular) Carleman estimates. We discuss numerical confirmation and open problems.

We report on new stability estimates for recovery of the near field from the scattering
amplitude and for Schroedinger potential from the Dirichlet-to Neumann map. In these
estimates unstable (logarithmic part) goes to zero as the wave number grows. Proofs
are using new bounds for Hankel functions and complex and real geometrical optics solutions.

【 場所 】 自然学系Ｄ棟　５０９教室