Ch flat curves in Euclidean space
Characterization of compact subsets of curves with ω-continuous derivatives
We give a characterization of compact subsets of finite unions of disjoint finite-length curves in ℝⁿ with ω-continuous derivative and without self-intersections. Intuitively, our condition can be formulated as follows: there exists a finite set of regular curves covering a compact set K iff every triple of points of K behaves like a triple of points of a regular curve. This work was inspired by theorems by Jones, Okikiolu, Schul and others that characterize compact subsets of...
Chords and arclength of a closed space curve
Circuminscribed polygons in a plane annulus
Each oval and a natural number n ≥ 3 generate an annulus which possesses the Poncelet's porism property. A necessary and sufficient condition of existence of circuminscribed n-gons in an annulus is given.
Classification of pencils of conics of type VI in the isotropic plane. (Klassifikationstheorie der Kegelschnittbüschel vom Typ VI der isotropen Ebene.)
Closed space curves of constant curvature consisting of arcs of circular helices.
Comment on curves in 2- and 3-dimensional Monkowski space.
Construction de la tangente en un point de la quadratrice
Construction der Hauptkrümmungshalbmesser und der Hauptkrümmungsreichtungen bei beliebigen Flächen
Curvatures and Curves in Hilbert Space.
Curvatures of conflict surfaces in Euclidean 3-space
This article extends to three dimensions results on the curvature of the conflict curve for pairs of convex sets of the plane, established by Siersma [3]. In the present case a conflict surface arises, equidistant from the given convex sets. The Gaussian, mean curvatures and the location of umbilic points on the conflict surface are determined here. Initial results on the Darbouxian type of umbilic points on conflict surfaces are also established. The results are expressed in terms of the principal...
Curve shortening flow and the Banchoff-Pohl inequality on surfaces of nonpositive curvature.
Curve shortening on surfaces
Curves in Banach spaces which allow a parametrization or a parametrization with finite convexity
We give a complete characterization of those (where is a Banach space) which allow an equivalent parametrization (i.e., a parametrization whose derivative has bounded variation) or a parametrization with bounded convexity. Our results are new also for . We present examples which show applicability of our characterizations. For example, we show that the and parametrization problems are equivalent for but are not equivalent for .
Curves in the lightlike cone.
Curves with finite turn
In this paper we study the notions of finite turn of a curve and finite turn of tangents of a curve. We generalize the theory (previously developed by Alexandrov, Pogorelov, and Reshetnyak) of angular turn in Euclidean spaces to curves with values in arbitrary Banach spaces. In particular, we manage to prove the equality of angular turn and angular turn of tangents in Hilbert spaces. One of the implications was only proved in the finite dimensional context previously, and equivalence of finiteness...
Cylindrical Tzitzeica curves implies forced harmonic oscillators.