Riemannian Optimization on Tree Tensor Networks with Application in Machine Learning
Published: Jul 29, 2025
Last Updated: Jul 29, 2025
Authors:Marius Willner, Marco Trenti, Dirk Lebiedz
Abstract
Tree tensor networks (TTNs) are widely used in low-rank approximation and quantum many-body simulation. In this work, we present a formal analysis of the differential geometry underlying TTNs. Building on this foundation, we develop efficient first- and second-order optimization algorithms that exploit the intrinsic quotient structure of TTNs. Additionally, we devise a backpropagation algorithm for training TTNs in a kernel learning setting. We validate our methods through numerical experiments on a representative machine learning task.