Romain Mottier

PhD student in Applied Mathematics for Computational Physics

I am a PhD student in applied mathematics for the numerical simulation of physics problems under the direction of Alexandre Ern at CERMICS, École des Ponts ParisTech. I am also co-supervised by Laurent Guillot at CEA (Fench Alternative Energies and Atomic Energy Comission).

Research Topic

I am particularly interested in the use of non conforming hybrid high order finite element methods (HDG/HHO) especially in the context of the use of unfitted meshes and the CUT paradigm (cut of mesh elements by material interfaces).

As part of my thesis, I am currently working within the framework of the simulation of the propagation of seismic-acoustic waves (coupling between the seismic field and atmospheric acoustics), using the methods mentioned above.

From a modeling point of view, I really like to vary the fields of application (fluid mechanics, structural mechanics, biology, electromagnetism, etc.) and to learn in these different fields.

I am also interested in the optimization and the portability of the numerical methods on high performance computing architectures.




•   2022 - 2023 :

  - Fall semester 2022 / Paris Sorbonne University
    1st year of Master's degree in Computational Mechanics
    Course : Numerical methods (Linear systems, Finite differences etc...)
    Teaching Assistantship : Supervision of practical work sessions and numerical modeling projects

  - Spring semester 2023 / Paris Dauphine University
    2nd year of Bachelor's degree in Mathematics and Computer science
    Course : Numerical methods (Nonlinear equations, polynomial interpolation, quadrature formulas,
    iterative and direct methods for solving linear systems, eigenvalue and eigenvector computing)
    Teaching Assistantship : Supervision of theoretical and practical work classes


I am currently enrolled in a PhD program at ENPC. The topic of my thesis is "Non-conforming hybrid methods for modeling and numerical simulation of seismic-acoustic wave propagation" .

I graduated from the master Modeling and Fluid-Structure Computation from the engineering school SeaTech. During my education I had several training experiences :

  • 6 months at ONERA (National Office for Aerospace Studies and Research) where I work on the implementation of Spectral Differences and CDO schemes for the resolution of Maxwell's equations - (France / 2021).

  • 6 months at UPC (Polytechnic University of Catalonia) in the Msc "Numerical Methods in Engineering" - (Spain / 2020).

  • 4 months at ESA (European Space Agency) where I worked on the implementation and the modeling of the near surface of Mercury, with application to heat transfer between the surface and the internal layers - (Netherlands / 2019).