MAKUTU

The computational geosciences encompass a wide variety of scientific activities aimed at tackling societal challenges such as water resources, energy supply, climate change and so on. They are based on observations, physical modelling and precise mathematical formulations. Considerable advances in scientific computing have made it possible to use extensive numerical simulations that provide tools based on wave measurements to study and eventually monitor complex environments that are otherwise difficult to probe and even unfathomable, for example the subsurface or the interior of stars. Bridging the gap between experimental measurements and numerical simulations is an important objective for Makutu, which seeks a balance between precision and efficiency according to the fields of application considered. A common strategy will be to develop frugal models using mathematical methods (asymptotic methods, artificial boundary conditions, reduction methods...), and efficient numerical schemes (in the time and harmonic domains, with analytical and high-order numerical methods). Makutu proposes a research program aimed at developing numerical software for recovering the physical properties of complex media, with a particular focus on the Earth and its natural reservoirs. In addition to the geophysical framework, Makutu's research program includes two other themes: solar imaging and aeroacoustics. For solar imaging, modeling is of great importance, and the team is working with different equations in a new mathematical formalism. New simulation codes are being developed with a long-term view to solving inverse problems. Given the similarities between seismic and solar imaging methods, software development is carried out in-house using many of the skills acquired by the team in the field of geophysical imaging. A strong collaboration exists with the Sun Institute of the Max Planck Institute in Göttingen. In the field of aeroacoustics, Makutu is collaborating with Airbus on the development of new simulation methods using approximation spaces containing the physical characteristics of the problem to be solved. The team, joint with TotalEnergies, brings together applied mathematicians and research engineers. It is shared between the Université de Pau et des Pays de l'Adour (UPPA), Inria and TotalEnergies, with involvement from Bordeaux INP and CNRS. The majority of Makutu's members are based in Pau, as the team is attached to LMAP (Laboratoire de Mathématiques et d'Applications de Pau, UMR CNRS 5142).