Maximum relative distance between symmetric rank-two and rank-one tensors

Henrik Eisenmann and André Uschmajew

Contact the author: Please use for correspondence this email.
Submission date: 24. Nov. 2021 (revised version: November 2021)
Pages: 16
Bibtex
Download full preprint: PDF (418 kB)

Abstract:
It is shown that the relative distance in Frobenius norm of a real symmetric order-d tensor of rank two to its best rank-one approximation is upper bounded by . This is achieved by determining the minimal possible ratio between spectral and Frobenius norm for symmetric tensors of border rank two, which equals ^(d−1)∕2. These bounds are also verified for nonsymmetric tensors of order d = 3.