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We show how to use formal desingularizations (defined earlier by the first author) in order to compute the global sections (also called adjoints) of twisted pluricanonical sheaves. These sections define maps that play an important role in…

Algebraic Geometry · Mathematics 2008-01-16 T. Beck , J. Schicho

Regular chains and triangular decompositions are fundamental and well-developed tools for describing the complex solutions of polynomial systems. This paper proposes adaptations of these tools focusing on solutions of the real analogue:…

Symbolic Computation · Computer Science 2010-05-17 Changbo Chen , James H. Davenport , John P. May , Marc Moreno Maza , Bican Xia , Rong Xiao

We introduce the concept of pseudo-trisections of smooth oriented compact 4-manifolds with boundary. The main feature of pseudo-trisections is that they have lower complexity than relative trisections for given 4-manifolds. We prove…

Geometric Topology · Mathematics 2025-02-19 Shintaro Fushida-Hardy

We present algorithms for computing strongly singular and near-singular surface integrals over curved triangular patches, based on singularity subtraction, the continuation approach, and transplanted Gauss quadrature. We demonstrate the…

Numerical Analysis · Mathematics 2024-06-24 Hadrien Montanelli , Francis Collino , Houssem Haddar

A fixed set of vertices in the plane may have multiple planar straight-line triangulations in which the degree of each vertex is the same. As such, the degree information does not completely determine the triangulation. We show that even if…

Computational Complexity · Computer Science 2025-10-07 Erin Chambers , Tim Ophelders , Anna Schenfisch , Julia Sollberger

We consider the problem of counting straight-edge triangulations of a given set $P$ of $n$ points in the plane. Until very recently it was not known whether the exact number of triangulations of $P$ can be computed asymptotically faster…

Computational Geometry · Computer Science 2014-04-02 Victor Alvarez , Karl Bringmann , Saurabh Ray , Raimund Seidel

Image triangulation, the practice of decomposing images into triangles, deliberately employs simplification to create an abstracted representation. While triangulating an image is a relatively simple process, difficulties arise when…

Computational Geometry · Computer Science 2024-08-30 Olivia Laske , Lori Ziegelmeier

A canonical branched covering over each sufficiently good simplicial complex is constructed. Its structure depends on the combinatorial type of the complex. In this way, each closed orientable 3-manifold arises as a branched covering over…

Geometric Topology · Mathematics 2007-05-23 Ivan Izmestiev , Michael Joswig

Counting Euclidean triangulations with vertices in a finite set $\C$ of the convex hull $\conv(\C)$ of $\C$ is difficult in general, both algorithmically and theoretically. The aim of this paper is to describe nearly convex polygons, a…

Combinatorics · Mathematics 2010-12-13 Roland Bacher , Frédéric Mouton

We propose new algorithms for computing triangular decompositions of polynomial systems incrementally. With respect to previous works, our improvements are based on a {\em weakened} notion of a polynomial GCD modulo a regular chain, which…

Symbolic Computation · Computer Science 2011-04-06 Changbo Chen , Marc Moreno Maza

We propose an efficient algorithm for computing a common eigenvector of a finite set of square matrices. As an immediate consequence we obtain an algorithm for determining whether the matrices admit a simultaneous triangulation, and, if so,…

Rings and Algebras · Mathematics 2023-09-27 Emanuel Malvetti

A branched covering map of surfaces induces a map in the opposite direction between their arc complexes. We represent a branched covering map combinatorially using what we call a lifting picture, and use this representation to computably…

Combinatorics · Mathematics 2020-09-15 Cyrus Peterpaul

We introduce and study a notion of decomposition of planar point sets (or rather of their chirotopes) as trees decorated by smaller chirotopes. This decomposition is based on the concept of mutually avoiding sets (which we rephrase as…

Computational Geometry · Computer Science 2024-06-12 Mathilde Bouvel , Valentin Féray , Xavier Goaoc , Florent Koechlin

This is the announcement, and the long summary, of a series of articles on the algorithmic study of Thurston maps. We describe branched coverings of the sphere in terms of group-theoretical objects called bisets, and develop a theory of…

Computational Complexity · Computer Science 2017-06-20 Laurent Bartholdi , Dzmitry Dudko

We present an algorithm for computing curves and families of curves of prescribed degree and geometric genus on real rational surfaces.

Algebraic Geometry · Mathematics 2018-05-11 Niels Lubbes

We propose a simple technique that, if combined with algorithms for computing functions of triangular matrices, can make them more efficient. Basically, such a technique consists in a specific scaling similarity transformation that reduces…

Numerical Analysis · Mathematics 2021-11-18 João R. Cardoso , Amir Sadeghi

Determining visibility in planar polygons and arrangements is an important subroutine for many algorithms in computational geometry. In this paper, we report on new implementations, and corresponding experimental evaluations, for two…

Computational Geometry · Computer Science 2014-03-18 Francisc Bungiu , Michael Hemmer , John Hershberger , Kan Huang , Alexander Kröller

We present algorithms to compute the topology of 2D and 3D hyperelliptic curves. The algorithms are based on the fact that 2D and 3D hyperelliptic curves can be seen as the image of a planar curve (the Weierstrass form of the curve), whose…

Geometric Topology · Mathematics 2019-10-29 Juan Gerardo Alcázar , Jorge Caravantes , Gema M. Diaz-Toca , Elias Tsigaridas

We describe the implementation of a subfield of the field of formal Puiseux series in polymake. This is employed for solving linear programs and computing convex hulls depending on a real parameter. Moreover, this approach is also useful…

Optimization and Control · Mathematics 2018-07-02 Michael Joswig , Georg Loho , Benjamin Lorenz , Benjamin Schröter

Given a set of disjoint simple polygons $\sigma_1, \ldots, \sigma_n$, of total complexity $N$, consider a convexification process that repeatedly replaces a polygon by its convex hull, and any two (by now convex) polygons that intersect by…

Computational Geometry · Computer Science 2019-12-11 Elias Dahlhaus , Sariel Har-Peled , Alan L. Hu