English
Related papers

Related papers: Principal binets

200 papers

In this paper are studied the nets of principal curvature lines on surfaces embedded in Euclidean $3-$space near their end points, at which the surfaces tend to infinity. This is a natural complement and extension to smooth surfaces of the…

Differential Geometry · Mathematics 2016-09-07 Jorge Sotomayor , Ronaldo Garcia

Discrete Koenigs nets are a special class of discrete surfaces that play a fundamental role in discrete differential geometry, in particular in the study of discrete isothermic and minimal surfaces. Recently, it was shown by Bobenko and…

Differential Geometry · Mathematics 2025-10-31 Niklas Christoph Affolter , Alexander Yves Fairley

We propose a natural discretisation scheme for classical projective minimal surfaces. We follow the classical geometric characterisation and classification of projective minimal surfaces and introduce at each step canonical discrete models…

Differential Geometry · Mathematics 2018-01-26 A. McCarthy , W. K. Schief

We describe the relation between two characterizations of conjugacy in groups of piecewise-linear homeomorphisms, discovered by Brin and Squier in [2] and Kassabov and Matucci in [5]. Thanks to the interplay between the techniques, we…

Group Theory · Mathematics 2014-01-10 Francesco Matucci

Discretization of curves is an ancient topic. Even discretization of curves with an eye toward differential geometry is over a century old. However there is no general theory or methodology in the literature, despite the ubiquitous use of…

Differential Geometry · Mathematics 2013-11-25 Daniel Carroll , Eleanor Hankins , Emek Köse , Ivan Sterling

We study the topological configurations of the lines of principal curvature, the asymptotic and characteristic curves on a cuspidal edge, in the domain of a parametrization of this surface as well as on the surface itself. Such…

Geometric Topology · Mathematics 2017-03-28 Kentaro Saji

The linearizability of differential equations was first considered by Lie for scalar second order semi-linear ordinary differential equations. Since then there has been considerable work done on the algebraic classification of linearizable…

Classical Analysis and ODEs · Mathematics 2008-04-25 Asghar Qadir

We present the first steps of a procedure which discretises surface theory in classical projective differential geometry in such a manner that underlying integrable structure is preserved. We propose a canonical frame in terms of which the…

Differential Geometry · Mathematics 2018-07-04 W. K. Schief , A. Szereszewski

We propose a discrete surface theory in $\mathbb R^3$ that unites the most prevalent versions of discrete special parametrizations. This theory encapsulates a large class of discrete surfaces given by a Lax representation and, in…

Differential Geometry · Mathematics 2014-12-24 Tim Hoffmann , Andrew O. Sageman-Furnas , Max Wardetzky

We consider congruences of straight lines in a plane with the combinatorics of the square grid, with all elementary quadrilaterals possessing an incircle. It is shown that all the vertices of such nets (we call them incircular or IC-nets)…

Metric Geometry · Mathematics 2017-10-30 Arseniy Akopyan , Alexander I. Bobenko

Congruences, or $2$-parameter families of lines in $3$-space are of interest in many situations, in particular in geometric optics. In this paper we consider elements of their geometry which are invariant under affine changes of…

Differential Geometry · Mathematics 2023-07-06 J. W. Bruce , F. Tari

The main goal of this note is to begin a systematic study on conic-line arrangements in the complex projective plane. We show a de Bruijn-Erd\H{o}s-type inequality and Hirzebruch-type inequality for a certain class of conic-line…

Algebraic Geometry · Mathematics 2022-04-13 Piotr Pokora , Tomasz Szemberg

We study Christoffel and Darboux transforms of discrete isothermic nets in 4-dimensional Euclidean space: definitions and basic properties are derived. Analogies with the smooth case are discussed and a definition for discrete Ribaucour…

dg-ga · Mathematics 2008-02-03 Udo Hertrich-Jeromin , Tim Hoffmann , Ulrich Pinkall

A novel class of discrete integrable surfaces is recorded. This class of discrete O surfaces is shown to include discrete analogues of classical surfaces such as isothermic, `linear' Weingarten, Guichard and Petot surfaces. Moreover,…

Exactly Solvable and Integrable Systems · Physics 2007-05-23 W. K. Schief

A line field on a manifold is a smooth map which assigns a tangent line to all but a finite number of points of the manifold. As such, it can be seen as a generalization of vector fields. They model a number of geometric and physical…

Geometric Topology · Mathematics 2017-12-29 Thomas Lewiner , Tiago Novello , Joao Paixao , Carlos Tomei

Canonical parametrisations of classical confocal coordinate systems are introduced and exploited to construct non-planar analogues of incircular (IC) nets on individual quadrics and systems of confocal quadrics. Intimate connections with…

Differential Geometry · Mathematics 2019-08-05 Arseniy V. Akopyan , Alexander I. Bobenko , Wolfgang K. Schief , Jan Techter

A smooth affine minimal surface with indefinite metric can be obtained from a pair of smooth non-intersecting spatial curves by Lelieuvre's formulas. These surfaces may present singularities, which are generically cuspidal edges and…

Differential Geometry · Mathematics 2024-01-15 Marcos Craizer

This paper proposes a novel regularization approach to bias Convolutional Neural Networks (CNNs) toward utilizing edge and line features in their hidden layers. Rather than learning arbitrary kernels, we constrain the convolution layers to…

Computer Vision and Pattern Recognition · Computer Science 2024-10-23 Christoph Linse , Beatrice Brückner , Thomas Martinetz

We consider the ill-posed inverse problem of identifying a nonlinearity in a time-dependent PDE model. The nonlinearity is approximated by a neural network, and needs to be determined alongside other unknown physical parameters and the…

Numerical Analysis · Mathematics 2022-11-23 Barbara Kaltenbacher , Tram Thi Ngoc Nguyen

In the projective plane, we consider congruences of straight lines with the combinatorics of the square grid and with all elementary quadrilaterals possessing touching inscribed conics. The inscribed conics of two combinatorially…

Algebraic Geometry · Mathematics 2019-11-21 Alexander I. Bobenko , Alexander Y. Fairley