Dr. Ralph Lteif is an assistant professor of mathematics in the Department of Computer Science and Mathematics. Dr. Lteif joined LAU as a full-time faculty in Fall 2024. He earned his PhD in Applied Mathematics through a joint doctoral program between the Lebanese University and Grenoble Alpes University in October 2016. He initially joined LAU as a part-time faculty member in 2018, teaching several courses such as Multivariate Calculus, Discrete Structures, Differential Equations, and Biostatistics. From 2020 to 2023, he served as a Postdoctoral Research Fellow at LAU. He later continued his postdoctoral research at the French National Institute for Research in Computer Science and Control (INRIA) in Bordeaux, France, from 2023 to 2024. 

Research Interests

His research is centered on the mathematical and numerical analysis of complex physical phenomena, particularly in the realm of fluid dynamics and wave propagation. His work involves the development and analysis of mathematical models, with a focus on partial differential equations (PDEs) governing free surface flows. He is also deeply engaged in the study of asymptotic models for oceanographic problems, and the development of numerical methods, such as Finite Volume and Finite Difference methods, for solving hyperbolic and nonlinear dispersive PDEs.

SDGs Research Mapping

Dr. Ralph Lteif conducts research relevant to the following SDGs:

Selected Publications

R. Lteif, An operator-splitting approach with a hybrid finite volume/ finite difference scheme for extended Boussinesq models, Applied Numerical Mathematics, 196 (2024), pp. 159-182.

R. Lteif, and S. Gerbi, A new class of higher-ordered/extended Boussinesq system for efficient numerical simulations by splitting operators, Applied Mathematics and Computation, 432 (2022), 127373.

R. Lteif, and B.Khorbatly, Medium amplitude model for internal waves over large topography variation, J. Math. Anal. Appl., 514 (2022), 126364.

B. Khorbatly, R. Lteif, S. Israwi, and S. Gerbi, Mathematical modeling and numerical analysis for the higher order Boussinesq system, ESAIM: M2AN 56 (2) 593-615 (2022).

R. Lteif, Well-balanced numerical resolution of the two-layer shallow water equations under rigid-lid with wet-dry fronts, Computers & Fluids, 235 (2022) 105277.

R. Lteif and S. Israwi. Coupled and scalar asymptotic models for internal waves over variable topography. Asymptotic Analysis, vol. 106, no. 2, pp. 61-98, (2018).

C. Bourdarias, S. Gerbi, and R. Lteif. A numerical scheme for an improved Green-Naghdi model in the Camassa-Holm regime for the propagation of internal waves. Computers & Fluids, 156:283-304, (2017).

C. Bourdarias, S. Gerbi, and R. Lteif. A Numerical Scheme for the Propagation of Internal Waves in an Oceanographic Model. In: Cancès C., Omnes P. (eds) Finite Volumes for Complex Applications VIII - Hyperbolic, Elliptic and Parabolic Problems. FVCA 2017. Springer Proceedings in Mathematics & Statistics, vol 200. Springer, Cham. 

R. Lteif, S. Israwi, and R. Talhouk. An improved result for the full justification of asymptotic models for the propagation of internal waves. Communications on pure and applied analysis, 14(6): 2203-2230, (2015). 

Academic Degrees

PhD in Applied Mathematics, Grenoble Alpes University and the Lebanese University.

MSc in Applied Mathematics, Lebanese University, Lebanon. 

BS in Mathematics, Lebanese University, Lebanon.