English
Related papers

Related papers: Real identifiability vs complex identifiability

200 papers

We prove (without exceptions) the existence of irredundant tensor decompositions with the number of addenda equal to rank $+1$. We also discuss the existence of decompositions with more than the tensor rank terms, which are concise, while…

Algebraic Geometry · Mathematics 2020-02-17 Edoardo Ballico

The decomposition locus of a tensor is the set of rank-one tensors appearing in a minimal tensor-rank decomposition of the tensor. For tensors lying on the tangential variety of any Segre variety, but not on the variety itself, we show that…

Algebraic Geometry · Mathematics 2024-07-26 Alessandra Bernardi , Alessandro Oneto , Pierpaola Santarsiero

We study path-connectedness and homotopy groups of sets of tensors defined by tensor rank, border rank, multilinear rank, as well as their symmetric counterparts for symmetric tensors. We show that over $\mathbb{C}$, the set of rank-$r$…

Algebraic Geometry · Mathematics 2018-04-24 Pierre Comon , Lek-Heng Lim , Yang Qi , Ke Ye

Hermitian tensors are natural generalizations of Hermitian matrices, while possessing rather different properties. A Hermitian tensor is separable if it has a Hermitian decomposition with only positive coefficients, i.e., it is a sum of…

Optimization and Control · Mathematics 2021-08-11 Mareike Dressler , Jiawang Nie , Zi Yang

We study the semialgebraic structure of $D_r$, the set of nonnegative tensors of nonnegative rank not more than $r$, and use the results to infer various properties of nonnegative tensor rank. We determine all nonnegative typical ranks for…

Rings and Algebras · Mathematics 2016-08-23 Yang Qi , Pierre Comon , Lek-Heng Lim

We study orthogonal decompositions of symmetric and ordinary tensors using methods from linear algebra. For the field of real numbers we show that the sets of decomposable tensors can be defined be equations of degree 2. This gives a new…

Rings and Algebras · Mathematics 2019-10-01 Pascal Koiran

Decompositions of higher-order tensors into sums of simple terms are ubiquitous. We show that in order to verify that two tensors are generated by the same (possibly scaled) terms it is not necessary to compute the individual…

Spectral Theory · Mathematics 2019-12-11 Ignat Domanov , Lieven De Lathauwer

Let T be a general complex tensor of format $(n_1,...,n_d)$. When the fraction $\prod_in_i/[1+\sum_i(n_i-1)]$ is an integer, and a natural inequality (called balancedness) is satisfied, it is expected that T has finitely many minimal…

Algebraic Geometry · Mathematics 2025-10-17 Jonathan D. Hauenstein , Luke Oeding , Giorgio Ottaviani , Andrew J. Sommese

Compressed sensing extends from the recovery of sparse vectors from undersampled measurements via efficient algorithms to the recovery of matrices of low rank from incomplete information. Here we consider a further extension to the…

Numerical Analysis · Mathematics 2014-11-04 Holger Rauhut , Reinhold Schneider , Zeljka Stojanac

In this paper we study the locus of singular tuples of a complex valued multisymmetric tensor. The main problem that we focus on is: given the set of singular tuples of some general tensor, which are all the tensors that admit those same…

Algebraic Geometry · Mathematics 2022-06-16 Ettore Teixeira Turatti

We describe the stratification by tensor rank of the points belonging to the tangent developable of any Segre variety. We give algorithms to compute the rank and a decomposition of a tensor belonging to the secant variety of lines of any…

Algebraic Geometry · Mathematics 2013-12-05 Edoardo Ballico , Alessandra Bernardi

Suppose we are given an $n$-dimensional order-3 symmetric tensor $T \in (\mathbb{R}^n)^{\otimes 3}$ that is the sum of $r$ random rank-1 terms. The problem of recovering the rank-1 components is possible in principle when $r \lesssim n^2$…

Computational Complexity · Computer Science 2023-03-28 Alexander S. Wein

We prove the existence of an open set of $n_1\times n_2 \times n_3$ tensors of rank $r$ on which a popular and efficient class of algorithms for computing tensor rank decompositions based on a reduction to a linear matrix pencil, typically…

Numerical Analysis · Mathematics 2022-09-02 Carlos Beltrán , Paul Breiding , Nick Vannieuwenhoven

Asymptotic tensor rank is notoriously difficult to determine. Indeed, determining its value for the $2\times 2$ matrix multiplication tensor would determine the matrix multiplication exponent, a long-standing open problem. On the other…

Computational Complexity · Computer Science 2024-11-26 Matthias Christandl , Koen Hoeberechts , Harold Nieuwboer , Péter Vrana , Jeroen Zuiddam

A symmetric tensor is a higher order generalization of a symmetric matrix. In this paper, we study various properties of symmetric tensors in relation to a decomposition into a sum of symmetric outer product of vectors. A rank-1 order-k…

Numerical Analysis · Mathematics 2008-09-02 Pierre Comon , Gene Golub , Lek-Heng Lim , Bernard Mourrain

We introduce the concise secant varieties, which are, informally speaking, modular partial desingularisations of secant varieties to Segre embeddings. More precisely, they are projective and birational to the abstract secant varieties, yet…

Algebraic Geometry · Mathematics 2026-04-29 Jakub Jagiełła , Joachim Jelisiejew

We study the subrank of real order-three tensors and give an upper bound to the subrank of a real tensor given its complex subrank. Using similar arguments to those used by Bernardi-Blekherman-Ottaviani, we show that all subranks between…

Algebraic Geometry · Mathematics 2025-03-24 Benjamin Biaggi , Jan Draisma , Sarah Eggleston

Tensor decompositions have become a central tool in data science, with applications in areas such as data analysis, signal processing, and machine learning. A key property of many tensor decompositions, such as the canonical polyadic…

Numerical Analysis · Mathematics 2025-05-20 Subhayan Saha , Giovanni Barbarino , Nicolas Gillis

We introduce a new criterion which tests if a given decomposition of a given ternary form $T$ of even degree is unique. The criterion is based on the analysis of the Hilbert function of the projective set of points $Z$ associated to the…

Algebraic Geometry · Mathematics 2020-07-21 Andrea Mazzon

Free tensors are tensors which, after a change of bases, have free support: any two distinct elements of its support differ in at least two coordinates. They play a distinguished role in the theory of bilinear complexity, in particular in…