Research Network

Dr. Ralph Lteif

Postdoctoral Research Fellow

I hold a PhD degree in Mathematics from the Lebanese University as well as the University of Grenoble in a joint doctoral program (October 2016).

My doctoral dissertation is entitled ” Modeling and mathematical

Analysis of models in oceanography”. In this thesis, I am interested in oceanographic problems and in particular in the propagation of internal waves at the interface between two layers of fluids over variable topography. More precisely, the goal is to introduce, study and rigorously justify asymptotic models in the shallow water regime in both theoretical and numerical aspects.

My research mainly focuses on Mathematical modeling and partial differential equations, Fluid mechanics, Asymptotic models for oceanographic problems, Hyperbolic systems, Nonlinear dispersive PDEs, Numerical methods for hyperbolic and dispersive equations.

I worked at several Lebanese universities as part-time instructor including LAU (2018 – present), USEK (2017 – 2020) and USJ (2017 – 2020)

Earlier this year I supervised the second year Master research project for two students in the Faculty of Sciences of Université Saint Joseph (USJ).

Rana el Arayeh with the subject tilted : -” Résolution numérique de modèle asymptotique pour la propagation d’onde internes”.

Joelle el Khoury with the subject tilted : -” Analyse mathématique et justification rigoureuse de modèles en océanographie”.

I also have 4 published articles in international journals and in conference proceedings with reviewing committee.




  1. R. TOUMA, R. LTEIF. Central finite volume methods for two layer flows with rigid lid. Preprint submitted to Applied Mathematics and Computation.
  2. R. LTEIF, S. ISRAWI. Coupled and scalar asymptotic models for internal waves over variable topography. Asymptotic Analysis, vol. 106, no. 2, pp. 61-98, 2018.
  3. R. LTEIF, S.GERBI, C. BOURDARIAS. 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.