The seminar of OBELIX team is currently held on thursdays 11:30 am, every two weeks, at the IRISA lab, Tohannic campus (bat. ENSIBS). Usually, the presentation lasts 30 min and is followed by a discussion with the team.
The seminar is coordinated by Yann CABANES: Please contact me for any information or if you want to present your work to our team.
Previous seminars
2019 / 2019-20 / 2020-21 / 2021-22 / 2022-23 / 2023-24 / 2024-25
Upcoming seminars (2024-25)
- Date: Thursday, April 3, 2025 at 11 a.m.
- Room: A104, ENSIBS Vannes
- Speaker: Thibault de Surrel
- Title: Wrapped Gaussian on the manifold of Symmetric Positive Definite matrices
- Abstract: Circular and non-flat data distributions are prevalent across diverse domains of data science, yet their specific geometric structures often remain underutilized in machine learning frameworks. A principled approach to accounting for the underlying geometry of such data is pivotal, particularly when extending statistical models, like the pervasive Gaussian distribution. In this presentation, I will tackle those issue by focusing on the manifold of symmetric positive definite matrices, a key focus in information geometry. I will introduced a non-isotropic wrapped Gaussian by leveraging the exponential map, derive theoretical properties of this distribution and propose a maximum likelihood framework for parameter estimation. Furthermore, I will reinterpret established classifiers on SPD through a probabilistic lens and introduce new classifiers based on the wrapped Gaussian model. This work lays the groundwork for extending classical machine learning and statistical methods to more complex and structured data.
