Beitr\ EMIS ELibM Electronic Journals Beiträge zur Algebra und Geometrie
Contributions to Algebra and Geometry
Vol. 49, No. 1, pp. 195-203 (2008)

Previous Article

Next Article

Contents of this Issue

Other Issues


ELibM Journals

ELibM Home

EMIS Home

 

A projective characterization of cyclicity

Wladimir G. Boskoff and Bogdan D. Suceava

Department of Mathematics and Computer Science, University Ovidius Constanta, Romania, e-mail: boskoff@univ-ovidius.ro, Department of Mathematics, California State University at Fullerton, Fullerton, CA, 92834--6850, U.S.A., e-mail: bsuceava@fullerton.edu

Abstract: In this note we obtain a new cyclicity criterion for four points in the Euclidean plane, by using algebraic and geometric structures induced in $\mathbb{C}^2$ by the two dimensional complex projective space. We show that if four points lie on a circle in the real plane, then the type-one isotropic lines intersect $z_2$-axis in four points of real cross ratio.

Classification (MSC2000): 51N15; 51M05

Full text of the article:


Electronic version published on: 26 Feb 2008. This page was last modified: 28 Jan 2013.

© 2008 Heldermann Verlag
© 2008–2013 FIZ Karlsruhe / Zentralblatt MATH for the EMIS Electronic Edition