PreprintCC BY-NC-ND 4.0arXiv
The border Waring rank of x1⋯ xn is 2n−1
Abstract
In this paper, we show that the border Waring rank of x1x2⋯ xn over fields of characteristic zero is exactly 2n−1. As a consequence, the classical polarization identity is an optimal Waring decomposition even if we allow limits. As a symmetric tensor, this monomial is identified with the n× n permanent tensor. However, the lower bound is proved via the higher-order Koszul flattening of the n× n determinant tensor, which is not symmetric.
Related
BibTeX
@misc{han2026border,
title = {{The border Waring rank of $x_1\cdots x_n$ is $2^n-1$}},
author = {Jong In Han},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.09141},
eprint = {2609.09141},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.09141},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - The border Waring rank of x_1⋯ x_n is 2^n−1
AU - Jong In Han
PY - 2026
DA - 2026/09/08
PB - arXiv
DO - 10.48550/arxiv.2609.09141
UR - https://arxiv.org/abs/2609.09141
AB - In this paper, we show that the border Waring rank of x_1x_2⋯ x_n over fields of characteristic zero is exactly 2^n−1. As a consequence, the classical polarization identity is an optimal Waring decomposition even if we allow limits. As a symmetric tensor, this monomial is identified with the n× n permanent tensor. However, the lower bound is proved via the higher-order Koszul flattening of the n× n determinant tensor, which is not symmetric.
ER -