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Main Authors: da Silva, Eliezer, Klami, Arto, Mesquita, Diego, Urteaga, Iñigo
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.14523
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author da Silva, Eliezer
Klami, Arto
Mesquita, Diego
Urteaga, Iñigo
author_facet da Silva, Eliezer
Klami, Arto
Mesquita, Diego
Urteaga, Iñigo
contents Selecting the latent dimensions (ranks) in tensor factorization is a central challenge that often relies on heuristic methods. This paper introduces a rigorous approach to determine rank identifiability in probabilistic tensor models, based on prior predictive moment matching. We transform a set of moment matching conditions into a log-linear system of equations in terms of marginal moments, prior hyperparameters, and ranks; establishing an equivalence between rank identifiability and the solvability of such system. We apply this framework to four foundational tensor-models, demonstrating that the linear structure of the PARAFAC/CP model, the chain structure of the Tensor Train model, and the closed-loop structure of the Tensor Ring model yield solvable systems, making their ranks identifiable. In contrast, we prove that the symmetric topology of the Tucker model leads to an underdetermined system, rendering the ranks unidentifiable by this method. For the identifiable models, we derive explicit closed-form rank estimators based on the moments of observed data only. We empirically validate these estimators and evaluate the robustness of the proposal.
format Preprint
id arxiv_https___arxiv_org_abs_2510_14523
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On the Identifiability of Tensor Ranks via Prior Predictive Matching
da Silva, Eliezer
Klami, Arto
Mesquita, Diego
Urteaga, Iñigo
Machine Learning
Statistics Theory
62A09, 62F15
G.3
Selecting the latent dimensions (ranks) in tensor factorization is a central challenge that often relies on heuristic methods. This paper introduces a rigorous approach to determine rank identifiability in probabilistic tensor models, based on prior predictive moment matching. We transform a set of moment matching conditions into a log-linear system of equations in terms of marginal moments, prior hyperparameters, and ranks; establishing an equivalence between rank identifiability and the solvability of such system. We apply this framework to four foundational tensor-models, demonstrating that the linear structure of the PARAFAC/CP model, the chain structure of the Tensor Train model, and the closed-loop structure of the Tensor Ring model yield solvable systems, making their ranks identifiable. In contrast, we prove that the symmetric topology of the Tucker model leads to an underdetermined system, rendering the ranks unidentifiable by this method. For the identifiable models, we derive explicit closed-form rank estimators based on the moments of observed data only. We empirically validate these estimators and evaluate the robustness of the proposal.
title On the Identifiability of Tensor Ranks via Prior Predictive Matching
topic Machine Learning
Statistics Theory
62A09, 62F15
G.3
url https://arxiv.org/abs/2510.14523