\(V\)-model of the isotropic plane (Q860236)

The author embeds the affine model \(M_a\) of the isotropic plane [cf. \textit{H. Sachs}, Ebene isotrope Geometrie. (Plane isotropic geometry). Braunschweig/Wiesbaden: Friedr. Vieweg \& Sohn (1987; Zbl 0625.51001)] into the projectively closed Euclidean plane and submits \(M_a\) to a general quadratic inversion and gets the \(V\)-model \(M_V\) of the isotropic plane. The absolute flag of \(M_a\) is transformed to a Euclidean circle with an incident point. The metric of \(M_V\) is derived from the metric of \(M_a\). Conics and circles of \(M_V\) are studied shortly. The considerations of the paper are illustrated in ten very attractive figures.