Helly-Type Theorems for Roughly Convex-Like Sets

Author: An Phan Thanh  

Publisher: Taylor & Francis Ltd

ISSN: 0163-0563

Source: Numerical Functional Analysis and Optimization, Vol.28, Iss.5-6, 2007-05, pp. : 553-558

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

For a given positive real number γ, a subset M of an n-dimensional Euclidean space is said to be roughly convex-like (with the roughness degree γ) if x0, x1 ∈ M and ‖x1 - x0‖ > γ imply ]x0, x1[ ∩M ≠ ∅. In this paper, we present Helly-type theorems for such sets and consider an open question about sets of constant width raised by Buchman and Valentine and Sallee (Croft, Falconer and Guy, Unsolved Problems in Geometry, Springer-Verlag, New York, 1991, pp. 131-132).