English
Related papers

Related papers: Projective isomorphisms between rational surfaces

200 papers

The projected subgradient method for constrained minimization repeatedly interlaces subgradient steps for the objective function with projections onto the feasible region, which is the intersection of closed and convex constraints sets, to…

Optimization and Control · Mathematics 2013-08-21 Yair Censor , Ran Davidi , Gabor T. Herman , Reinhard W. Schulte , Luba Tetruashvili

Given a family of rational curves depending on a real parameter, defined by its parametric equations, we provide an algorithm to compute a finite partition of the parameter space (${\Bbb R}$, in general) so that the shape of the family…

Symbolic Computation · Computer Science 2009-11-13 Juan Gerardo Alcazar

We consider the parameterization ${\mathbf{f}}=(f_0,f_1,f_2)$ of a plane rational curve $C$ of degree $n$, and we want to study the singularities of $C$ via such parameterization. We do this by using the projection from the rational normal…

Algebraic Geometry · Mathematics 2017-05-19 Alessandra Bernardi , Alessandro Gimigliano , Monica Idà

Topological physics desires stable methods to measure the polarization singularities in optical vector fields. Here a periodic plasmonic metasurface is proposed to perform divergence computation of vectorial paraxial beams. We design such…

Optics · Physics 2020-09-09 Yijie Lou , Yisheng Fang , Zhichao Ruan

Regular algebraic surfaces isogenous to a higher product of curves can be obtained from finite groups with ramification structures. We find unmixed ramification structures for finite groups constructed as p-quotients of particular infinite…

Group Theory · Mathematics 2011-09-29 Nathan Barker , Nigel Boston , Norbert Peyerimhoff , Alina Vdovina

Let X be a smooth projective toric surface, and H^d(X) the Hilbert scheme parametrising the length d zero-dimensional subschemes of X. We compute the rational Chow ring A^*(H^d(X))\_Q. More precisely, if T is the two-dimensional torus…

Algebraic Geometry · Mathematics 2007-05-23 Laurent Evain

Fake projective planes are smooth complex surfaces of general type with Betti numbers equal to that of the usual projective plane. Recent explicit constructions of fake projective planes embed them via their bicanonical embedding in…

Algebraic Geometry · Mathematics 2023-03-20 Lev Borisov , Zachary Lihn

We prove (under some technical assumptions) that each surface in $\mathbb R^3$ containing two arcs of parabolas with axes parallel to $Oz$ through each point has a parametrization…

Differential Geometry · Mathematics 2022-09-08 Egor Morozov

The goal of this paper is to introduce a new constructive geometric proof of the affine version of Chevalley's Theorem. This proof is algorithmic and a verbatim implementation resulted in an efficient code for computing the constructible…

Algebraic Geometry · Mathematics 2022-01-14 Mohamed Barakat , Markus Lange-Hegermann

Many algorithms for surface registration risk producing significant errors if surfaces are significantly nonisometric. Manifold learning has been shown to be effective at improving registration quality, using information from an entire…

Graphics · Computer Science 2021-01-13 Robert J. Ravier

We provide first the functional analysis background required for reduced order modeling and present the underlying concepts of reduced basis model reduction. The projection-based model reduction framework under affinity assumptions,…

Numerical Analysis · Mathematics 2023-08-30 Gianluigi Rozza , Martin Hess , Giovanni Stabile , Marco Tezzele , Francesco Ballarin

We examine maps between noncommutative projective spaces. A surjection of graded rings A-->A/J induces a closed immersion Proj(A/J)-->Proj(A). A homomorphism f:A-->B between graded rings induces an affine map U --> Proj(A) from a non-empty…

Quantum Algebra · Mathematics 2007-05-23 S. Paul Smith

In the nineties, several methods for dealing in a more efficient way with the implicitization of rational parametrizations were explored in the Computer Aided Geometric Design Community. The analysis of the validity of these techniques has…

Commutative Algebra · Mathematics 2014-01-27 Carlos D'Andrea

Generalizable neural implicit surface reconstruction aims to obtain an accurate underlying geometry given a limited number of multi-view images from unseen scenes. However, existing methods select only informative and relevant views using…

Computer Vision and Pattern Recognition · Computer Science 2024-05-20 Youngju Na , Woo Jae Kim , Kyu Beom Han , Suhyeon Ha , Sung-eui Yoon

Illumination of scenes is usually generated in computer graphics using polygonal meshes. In this paper, we present a geometric method using projections. Starting from an implicit polynomial equation of a surface in 3-D or a curve in 2-D, we…

Computational Geometry · Computer Science 2026-04-03 Michal Zamboj , Jakub Řada

We study cubic rational maps that take lines to plane curves. A complete description of such cubic rational maps concludes the classification of all planarizations, i.e., maps taking lines to plane curves.

Algebraic Geometry · Mathematics 2014-09-12 Vsevolod Petrushchenko , Vladlen Timorin

We classify completely the surfaces of general type whose canonical map is 3-to-1 onto a surface of minimal degree in projective space. These surfaces fall into 5 distinct classes and we give explicit examples belonging to each of these…

Algebraic Geometry · Mathematics 2007-05-23 M. Mendes Lopes , R. Pardini

The aim of this article is to introduce a new methodology for constructing morphings between shapes that have identical topology. The morphings are obtained by deforming a reference shape, through the resolution of a sequence of linear…

Numerical Analysis · Mathematics 2025-02-04 Abbas Kabalan , Fabien Casenave , Felipe Bordeu , Virginie Ehrlacher , Alexandre Ern

We generalize an inequality for convex lattice polygons -- aka toric surfaces -- to general rational surfaces.

Algebraic Geometry · Mathematics 2013-06-17 Christian Haase , Josef Schicho

In this article, we study the geometry of plane curves obtained by three sections and another section given as their sum on certain rational elliptic surfaces. We make use of Mumford representations of semi-reduced divisors in order to…

Algebraic Geometry · Mathematics 2021-10-14 Ryosuke Masuya