Special Session 155: 

Unconditionally convergent $L1$-Galerkin FEMs for nonlinear time-fractional Schr\\{o}dinger equations

Dongfang Li
Huazhong University of Science and Technology
Peoples Rep of China
Co-Author(s):    Jilu Wang, Jiwei Zhang
Abstract:
In this paper, a linearized $L1$-Galerkin finite element method is proposed to solve the multi-dimensional nonlinear time-fractional Schr\{o}dinger equation. In terms of a temporal-spatial error splitting argument, we prove that the finite element approximations in $L^2$-norm and $L^\infty$-norm are bounded without any time stepsize conditions. More importantly, by using a discrete fractional Gronwall type inequality, optimal error estimates of the numerical schemes are obtained unconditionally, while the classical analysis for multi-dimensional nonlinear fractional problems always required certain time-step restrictions dependent on the spatial mesh size. Numerical examples are given to illustrate our theoretical results.