Armand Leclerc
Institute of Science and Technology Austria (ISTA)

Abstract

Seismology of stars and of the Sun is astronomers’ best and only observational way into their interiors, which allowed them to reach an accurate understanding of their structures and life cycles. Studying the mechanical waves propagating inside stars made us able to interpret the ringing spectrum of their surface, observed through variations in their light-curves, and to constrain many key physical processes. In my research, I investigate a new branch of the study of waves in stars by analyzing them through the lens of topology.

Wave topology is a theoretical framework created first in condensed matter physics and quantum contexts, which yields new results on the behavior of waves in inhomogeneous media from their topological properties. The most salient power of this technique is the characterization of so-called topological waves, which have unique properties like unidirectionality or spatial trapping. These concepts and ideas have reached other disciplines of physics in recent years, and I adapted this framework for the purpose of solar and stellar seismology applications, but also in planetary or discs dynamics.

In this presentation, I will give an overview of wave topology and how it can be applied to waves in stars to push further the limits of what we can learn from them. I will then present the most important results obtained with this new analysis of stellar oscillations. This sheds a new light on some of their properties, which in the case of the Sun gives a promising way to resolve the currently open problem of angular momentum transport in stars. These tools also allow us to predict waves of new kinds in planets such as Saturn, and in protoplanetary discs.

2026 November 24, 11:00

IA/U.Porto
Centro de Astrofísica da Universidade do Porto (Auditorium)
Rua das Estrelas, 4150-762 Porto