3 papers
math.RA2026
On the rank of quaternion Hankel matrices
Philippe Flores, Julien Flamant, Nicolas Le Bihan
This paper discusses the left and right ranks of quaternion matrices with Hankel structure. While they are in general different for arbitrary quaternion matrices, we show that the…
math.NA2025
Multilinear analysis of quaternion arrays: theory and computation
Julien Flamant, Xavier Luciani, Sebastian Miron +1
Multidimensional quaternion arrays (often referred to as "quaternion tensors") and their decompositions have recently gained increasing attention in various fields such as color an…
eess.SP2025
Time and covariance smoothing for restoration of bivariate signals
Yusuf Yigit Pilavci, Pierre Palud, Julien Flamant +3
In many applications and physical phenomena, bivariate signals are polarized, i.e. they trace an elliptical trajectory over time when viewed in the 2D planes of their two component…