An explicit characterization of isochordal-viewed multihedgehogs with circular isoptics

A curve α is called (ϕ, ℓ)-isochordal viewed if a straight segment of constant length ℓ can slide with its endpoints on α and such that their tangents to α at these endpoints make a constant angle ϕ. These tangents determine the so-called ϕ-isoptic curve of α. In this paper, an explicit characteriza...

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Bibliographic Details
Author: Rochera, D.
Format: article
Status:Versión enviada para evaluación y publicación
Publication Date:2023
Country:España
Institution:Basque Center for Applied Mathematics (BCAM)
Repository:BIRD. BCAM's Institutional Repository Data
OAI Identifier:oai:bird.bcamath.org:20.500.11824/1577
Online Access:http://hdl.handle.net/20.500.11824/1577
https://doi.org/10.1016/j.jmaa.2023.127107
Access Level:Embargoed access
Keyword:Isoptic curves
Isochordal-viewed curves
Curves of constant Φ-width
Support function
Hedgehogs
Regular polygons
Description
Summary:A curve α is called (ϕ, ℓ)-isochordal viewed if a straight segment of constant length ℓ can slide with its endpoints on α and such that their tangents to α at these endpoints make a constant angle ϕ. These tangents determine the so-called ϕ-isoptic curve of α. In this paper, an explicit characterization of all (ϕ, ℓ)-isochordal-viewed multihedgehogs with circular ϕ-isoptics is provided by their support functions, which are obtained as the solutions of a differential equation. This allows to construct any example of these curves in a very simple way from some free parameters. In addition, it is shown that a regular polygon of side length ℓ can slide smoothly along these multihedgehogs.