English

Skew-Parameterized Geometric Constants in Banach Spaces

Functional Analysis 2026-08-02 v1

Abstract

Building on the family of geometric constants introduced by Amini-Harandi and Rahimi, we define a skew-parameterized family on real normed spaces by replacing the classical symmetric pair with a rotated coefficient pair. This modification reveals new extremal behavior, particularly for asymmetric homogeneous weight functions. We establish reduction formulas, comparison inequalities, and parameter-stability estimates. Under an appropriate differential balance condition, we determine the exact values of these constants on Hilbert spaces and obtain a converse characterization in dimensions at least three. We further derive sufficient conditions for uniform non-squareness and normal structure, together with explicit computations in classical normed spaces. These results provide a unified framework for detecting Hilbertian and fixed-point-related geometric properties of Banach spaces.

Cite

@article{arxiv.2608.00933,
  title  = {Skew-Parameterized Geometric Constants in Banach Spaces},
  author = {Qing Du and Wenwen Zhang and Zhiyao Fang and Qi Liu},
  journal= {arXiv preprint arXiv:2608.00933},
  year   = {2026}
}