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arXiv · 2610.03050

Skew Schäffer Type Constants

Ying Xu·Qi Liu
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Abstract

We introduce the skew Schäffer type constant as an infimal counterpart of the recently developed skew James type constant \cite{RaoWuLiuNiWang} and establish its basic geometric theory in Banach spaces. The new constant admits sharp universal bounds and characterizes uniform nonsquareness through a strict gap condition. Exact values are obtained in Hilbert and Lebesgue spaces, where an exact relation with the skew James type constant is established. We further derive a James-modulus estimate leading to sufficient conditions for uniform normal structure.

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Ying Xu, Qi Liu. 2026-10-02. Skew Schäffer Type Constants. https://arxiv.org/abs/2610.03050

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