English

How orthogonality influences geometric constants

Functional Analysis 2025-08-26 v4

Abstract

In this paper, based on isosceles orthogonality, we have found equivalent definitions for four constants: A2(X)A_2(X) proposed by Baronti in 2000 [J. Math. Anal. Appl. 252(2000), 124-146], CNJ(X)C'_{\mathrm{NJ}}(X) introduced by Alonso et al. in 2008 [Stud. Math. 188(2008), 135-150], T(X)T(X) introduced by Alonso et al. in 2008 [J. Math. Anal. Appl. 340(2008), 1271-1283] and LYJ(X)L'_{\mathrm{YJ}}(X) put forward by Liu et al. in 2022 [Bull. Malays. Math. Sci. Soc., 45(2022),307-321]. A core commonality among these three constants is that they are all restricted to the unit sphere. This finding provides us with an insight: could it be that several constants defined over the entire space, when combined with orthogonality conditions, are equivalent to being restricted to the unit sphere?

Cite

@article{arxiv.2507.17122,
  title  = {How orthogonality influences geometric constants},
  author = {Yuxin Wang and Qi Liu and Mengmeng Bao},
  journal= {arXiv preprint arXiv:2507.17122},
  year   = {2025}
}
R2 v1 2026-07-01T04:14:28.855Z