Chennai Mathematical Institute

Seminars




Seminar Announcement
Date: Friday, 04 April 2025
Time: 2:00 PM
Venue: Seminar Hall
State-space models as graphs

Victor Elvira
University of Edinburgh, United Kingdom.
04-04-25


Abstract

Modelling and inference in multivariate time series is central in statistics, signal processing, and machine learning. A fundamental question when analysing multivariate sequences is the search for relationships between their entries (or the modelled hidden states), especially when the inherent structure is a directed (causal) graph. In such context, graphical modelling combined with sparsity constraints allows to limit the proliferation of parameters and enables a compact data representation which is easier to interpret in applications, e.g., in inferring causal relationships of physical processes in a Granger sense. In this talk, we present a novel perspective consisting on state-space models being interpreted as graphs. Then, we propose novel algorithms that exploit this new perspective for the estimation of the linear matrix operator and also the covariance matrix in the state equation of a linear-Gaussian state-space model. Finally, we discuss the extension of this perspective for the estimation of other model parameters in more complicated models.