English

A new geometric constant to compare p-angular and skew p-angular distances

Functional Analysis 2025-04-03 v1

Abstract

The pp-angular distance was first introduced by Maligranda in 2006, while the skew pp-angular distance was first introduced by Rooin in 2018. In this paper, we shall introduce a new geometric constant named Maligranda-Rooin constant in Banach spaces to compare pp-angular distance and skew pp-angular distance. We denote the Maligranda-Rooin constant as MRp(X)\mathcal{M} \mathcal{R}_p(\mathcal{X}). First, the upper and lower bounds for the MRp(X)\mathcal{M} \mathcal{R}_p(\mathcal{X}) constant is given. Next, it's shown that, a normed linear space is an inner space if and only if MRp(X)=1\mathcal{M} \mathcal{R}_p(\mathcal{X})=1. Moreover, an equivalent form of this new constant is established. By means of the MRp(X)\mathcal{M} \mathcal{R}_p(\mathcal{X}) constant, we carry out the quantification of the characterization of uniform nonsquareness. Finally, we study the relationship between the MRp(X)\mathcal{M} \mathcal{R}_p(\mathcal{X}) constant, uniform convexity, uniform smooth and normal structure.

Cite

@article{arxiv.2504.01267,
  title  = {A new geometric constant to compare p-angular and skew p-angular distances},
  author = {Yuxin Wang and Qi Liu and Jinyu Xia and Muhammad Sarfraz},
  journal= {arXiv preprint arXiv:2504.01267},
  year   = {2025}
}
R2 v1 2026-06-28T22:43:10.885Z