26–30 juin 2023
IMT
Fuseau horaire Europe/Paris

How to estimate a covariance matrix? Hopefully in large dimensions.

30 juin 2023, 09:30
1h
Salle Johnson (bât. 1R3, 1er étage) (IMT)

Salle Johnson (bât. 1R3, 1er étage)

IMT

Orateur

Reda Chhaibi

Description

Consider the basic operation of estimating the spectrum of large covariance matrices.
This estimation has an inherent "large dimensional bias", when one observes a multivariate sample whose size is comparable to the dimension.
Solving this issue amounts to understanding free multiplicative deconvolution.
Our work follows the footsteps of El Karoui, Arizmendi-Tarrago-Vargas and Ledoit-Péché.

After presenting their work, we will discuss the pros and cons of the methods.
Then
1) we will exhibit our own method for computable and statistically consistent estimation.
2) present a cramer-Rao lower bound

This is work in progress. Feedback from the audience will be required.

Documents de présentation

Aucun document.