Pierre Marchand

Pierre Marchand

Research Associate in applied mathematics

University of Bath


I am a postdoctoral researcher at the University of Bath, where I am working with Euan Spence. I am part of the EPSRC-funded project At the interface between semiclassical analysis and numerical analysis of wave propagation problems.

My research focuses on wave propagation problems, Decomposition Domain Methods (DDM) and Boundary Integral Equations (BIE). I am also developing a library for hierarchical matrix techniques called Htool with a parallelized matrix-vector product using MPI. It can be used via FreeFEM for solving BIEs, via PETSc for black-box compression, and directly via C++ or its Python interface.

Previously, I did my Ph.D under the supervision of Xavier Claeys and Frédéric Nataf at Laboratoire Jacques-Louis Lions ( LJLL) in Sorbonne Université, and I was a member of the joint Inria-LJLL project team Alpines. My thesis was funded by the ANR (French National Research Agency) via the ANR project NonlocalDD.


  • Wave propagation problems
  • Domain Decomposition Methods
  • Boundary Integral Equations
  • Numerical analysis
  • Scientific Computing
  • Computer tools


  • PhD in applied mathematics, 2020

    Sorbonne Université

  • Master's degree in applied mathematics, 2016

    Sorbonne Université

  • Engineer's degree, 2016

    École Nationale des Ponts et Chaussées

Recent Publications

(2021). Eigenvalues of the truncated Helmholtz solution operator under strong trapping. SIAM J. Math. Anal., accepted.

Preprint arXiv

(2020). Two-level preconditioning for h-version boundary element approximation of hypersingular operator with GenEO. Numerische Mathematik, Sep 2020, Vol. 146, Issue 3, Pages 597-628.

Preprint DOI HAL

(2020). Boundary integral multi-trace formulations and Optimised Schwarz Methods. Computers & Mathematics with Applications, June 2020, Vol. 79, Issue 11, Pages 3241-3256.

Preprint PDF Code DOI HAL

Conference talks


Computer tools

computer tools for mathematicians and computer scientists


Library for parallel hierarchical matrices


Research project conducted during the summer school CEMRACS in 2016


2017-2018 at Université Pierre et Marie Curie

2016-2017 at Université Pierre et Marie Curie

  • M1 : Calcul scientifique pour les grands systèmes linéaires [4M053]
    36 hours – lecturer: Xavier Claeys
  • M1 : Mise en oeuvre de la méthode des éléments finis [4M054]
    36 hours – lecturer: Xavier Claeys


  • Department of Mathematical Sciences
    University of Bath
    Bath, BA2 7AY
    United Kingdom
  • Enter Building 4W and take the stairs to Office 200 on Floor 5