On geometric invariants of plane curves (original) (raw)

On computational complexity of plane curve invariants

2014

The theory of generic smooth closed plane curves initiated by Vladimir Arnold is a beautiful fusion of topology, combinatorics, and analysis. The theory remains fairly undeveloped. We review existing methods to describe generic smooth closed plane curves combinatorially, introduce a new one, and give an algorithm for efficient computation of Arnold’s invariants. Our results provide a good source of future research projects that involve computer experiments with plane curves. The reader is not required to have background in topology and even undergraduate students with basic knowledge of differential geometry and graph theory will easily understand our paper.

Fundamental limitations on projective invariants of planar curves

IEEE Transactions on Pattern Analysis and Machine Intelligence, 1995

In this paper, some fundamental limitations of projective invariants of non-algebraic planar curves are discussed. It is shown that all curves within a large class can be mapped arbitrarily close to a circle by projective transformations. It is also shown that arbitrarily close to each of a finite number of closed planar curves there is one member of a set of projectively equivalent curves. Thus a continuous projective invariant on closed curves is constant. This also limits the possibility of finding so called projective normalisation schemes for closed planar curves. Index Items-Projective and afine invariants, recognition, Hausdorff metric.

The Analytic Classification of Plane Curves

arXiv (Cornell University), 2020

In this paper, we present a solution to the problem of the analytic classification of germs of plane curves with several irreducible components. Our algebraic approach follows precursive ideas of Oscar Zariski and as a subproduct allow us to recover some particular cases found in the literature.

On rigid plane curves

European Journal of Mathematics, 2015

In the article, we exhibit a series of new examples of rigid plane curves, that is, curves, whose collection of singularities determines them almost uniquely up to a projective transformation of the plane.

Affine Differential Invariants for Planar Curves

Balkan Journal of Geometry and its applications, 2002

The differential invariants associated with a transformation group on a manifold are the fundamental building blocks for understanding the geometry, equivalence, sym-metry and other properties of submanifolds. The basic theory of differential invariants dates back to the work of Lie, ...

Regular algebraic curve segments (I)—Definitions and characteristics

Computer Aided Geometric Design, 2000

In this paper (part one of a trilogy), we introduce the concept of a discriminating family of regular algebraic curves (real, nonsingular and connected). Several discriminating families are obtained by different characterizations of the zero contours of the Bernstein-Bezier (BB) form of bivariate polynomials over the plane triangle and quadrilateral. Algorithms for the graphics display of these regular curve families are also provided.

Remarks on double points of plane curves

Geometriae Dedicata

We study the relation between the type of a double point of a plane curve and the curvilinear 0-dimensional subschemes of the curve at the point. An Algorithm related to a classical procedure for the study of double points via osculating curves is described and proved. Eventually we look for a way to create examples of rational plane curves with given singularities A_s$$ A s .

On invariants of curves in centro-affine geometry

Journal of Mathematics of Kyoto University, 2004

Let GL(n, R) be the general linear group of n × n real matrices. Definitions of GL(n, R)-equivalence and the centro-affine type of curves are introduced. All possible centro-affine types are founded. For every centro affine type all invariant parametrizations of a curve are described. The problem of GL(n, R)-equivalence of curves is reduced to that of paths. A generating system of the differential field of invariant differential rational functions of a path is described. They can be viewed as centro-affine curvatures of a path. Global conditions of GL(n, R)equivalence of curves are given in terms of the centro-affine type and the generating differential invariants. Independence of elements of the generating differential invariants is proved.