Abstract
We introduce the notion of a firm non-expansive mapping in weak metric spaces, extending previous work for Banach spaces and certain geodesic spaces. We prove that, for firm non-expansive mappings, the minimal displacement, the linear rate of escape, and the asymptotic step size are all equal. This generalises a theorem by Reich and Shafrir.
| Original language | English |
|---|---|
| Pages (from-to) | 389-400 |
| Journal | Archiv der Mathematik |
| Volume | 119 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Oct 2022 |
| MoE publication type | A1 Journal article-refereed |
Funding
The first author acknowledges financial support from the Vilho, Yrjö and Kalle Väisälä Foundation of the Finnish Academy of Science and Letters, and from the Otto A. Malm Foundation.
Keywords
- firm nonexpansive
- firmly nonexpansive
- metric functional
- nonexpansive mapping
- weak metric
- metric spaces
- metric geometry