Understanding the growth of bar and spiral instabilities in galaxies: the case of the Milky Way

Supervision

Benoit Famaey (OBAS, Strasbourg)

Laurent Navoret (IRMA, Strasbourg)

Laboratory and team

OBAS, Strasbourg - Team "GALHECOS"

Subject description

This thesis will investigate bar and spiral arm instabilities in disk galaxies. While modern cosmological simulations reproduce many galaxy properties, they struggle with accurately reproducing bars. The Milky Way, a barred disk galaxy, has recently had its bar and spiral arm properties precisely determined (Khalil et al. 2024, arXiv:2411.12800). This thesis aims to reconstruct the Milky Way's past stellar disk state using the Vlasov-Poisson equation system to model its 4D (2D2V) phase-space evolution, initially excluding gas. Linear perturbation theory and backward integration will track the growth of instabilities, while Physics Informed Neural Networks (PINNs), validated against N-body simulations, will allow us to efficiently explore parameter space. A new patch for the RAMSES hydrodynamics code will simulate gas accretion, and the findings will allow us to refine our models.

Related mathematical skills

Linear algebra; Partial differential equations; Galactic dynamics; System of Vlasov-Poisson equations; N-body gravitational dynamics; Hydrodynamics

IRMIA++ is one of the 15 Interdisciplinary Thematic Institute (ITI) of the University of Strasbourg. It brings together a research cluster and a master-doctorate training program, relying on 12 research teams and 9 master tracks.

It encompasses all mathematicians at Université de Strasbourg, with partners in computer science and physics. ITI IRMIA++ builds on the internationally renowned research in mathematics in Strasbourg, and its well-established links with the socio-economic environment. It promotes interdisciplinary academic collaborations and industrial partnerships.

A core part of the IRMIA++ mission is to realize high-level training through integrated master-PhD tracks over 5 years, with common actions fostering an interdisciplinary culture, such as joint projects, new courses and workshops around mathematics and its interactions.

Selection will rely on the professional project of the candidate, his/her interest for interdisciplinarity and academic results.