Levenberg–Marquardt method for non-smooth ill-posed inverse problems in Banach spaces
Người báo cáo: Vũ Hữu Nhự (Đại học Phenikaa)

Thời gian: 9h00, thứ 4, ngày 17/11/2021

theo hình thức trực tuyến.

Tóm tắt: In this talk, we propose a Levenberg–Marquardt method with general regularization terms that are uniformly convex on bounded sets to solve the ill-posed inverse problems in Banach spaces, where the forward mapping might not be Gateaux differentiable and the image space is unnecessarily reflexive. The method therefore extends the one proposed by Jin and Yang in (Numer. Math. 133:655–684, 2016) for smooth inverse problem setting with globally uniformly convex regularization terms. We prove a novel convergence analysis of the proposed method under some standing assumptions, in particular, the generalized tangential cone condition and a compactness assumption. All these assumptions are fulfilled when investigating the identification of the heat source for semilinear elliptic boundary-value problems with a Robin boundary condition, a heat source acting on the boundary, and a possibly non-smooth nonlinearity. Therein, the Clarke subdifferential of the non-smooth nonlinearity is employed to construct the family of bounded operators that is a replacement for the non-existing Gateaux derivative of the forward mapping. The efficiency of the proposed method is illustrated with a numerical example.