PreprintCC BY 4.0arXiv
Zonoids whose polars are zonoids: the Banach--Mazur distance need not tend to one
Abstract
For every n≥2, we consider a Gaussian zonoid of revolution Zn arising from works of Vitale and Mathis. We prove that Zn* is also a zonoid and compute the Banach--Mazur distance from Zn to the Euclidean ball. This distance is independent of the dimension and is approximately $1.10$. Consequently, the supremal Banach--Mazur distance among zonoids whose polars are zonoids does not converge to $1$. The construction also produces a separable real Banach space X, not isometric to a Hilbert space, such that both X and X* embed linearly isometrically into L1.
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BibTeX
@misc{ryabogin2026zonoids,
title = {{Zonoids whose polars are zonoids: the Banach--Mazur distance need not tend to one}},
author = {Dmitry Ryabogin and Artem Zvavitch},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.10852},
eprint = {2609.10852},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.10852},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Zonoids whose polars are zonoids: the Banach--Mazur distance need not tend to one
AU - Dmitry Ryabogin
AU - Artem Zvavitch
PY - 2026
DA - 2026/09/09
PB - arXiv
DO - 10.48550/arxiv.2609.10852
UR - https://arxiv.org/abs/2609.10852
AB - For every n≥2, we consider a Gaussian zonoid of revolution Z_n arising from works of Vitale and Mathis. We prove that Z_n^* is also a zonoid and compute the Banach--Mazur distance from Z_n to the Euclidean ball. This distance is independent of the dimension and is approximately $1.10$. Consequently, the supremal Banach--Mazur distance among zonoids whose polars are zonoids does not converge to $1$. The construction also produces a separable real Banach space X, not isometric to a Hilbert space, such that both X and X^* embed linearly isometrically into L_1.
ER -