A counting formula for extreme contractions on regular polygonal Banach spaces

Authors

  • Lakshmi Kanta Dey National Institute of Technology Durgapur, Department of Mathematics
  • Subhadip Pal National Institute of Technology Durgapur, Department of Mathematics
  • Saikat Roy Indian Institute of Science Bangalore
DOI: https://doi.org/10.54330/afm.163218

Keywords:

Polygonal Banach space, extreme contraction, support functional, isometry

Abstract

A regular polygonal Banach space \(X\) is a two-dimensional real Banach space whose unit sphere is a regular polygon. We prove that the number of extreme contractions on a regular \(2n\)-gonal Banach space is \(2n^2+4n\). A characterization of extreme contractions on \(X\) is also presented.
Issue
Vol. 50 No. 1 (2025)
Section
Articles

Published

2025-07-01

How to Cite

Dey, L. K., Pal, S., & Roy, S. (2025). A counting formula for extreme contractions on regular polygonal Banach spaces. Annales Fennici Mathematici, 50(1), 389–405. https://doi.org/10.54330/afm.163218

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