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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

The notion of a tamely ramified covering is canonical only for curves. Several notions of tameness for coverings of higher dimensional schemes have been used in the literature. We show that all these definitions are essentially equivalent.…

Algebraic Geometry · Mathematics 2009-08-11 Moritz Kerz , Alexander Schmidt

For each pseudo-Anosov map $\phi$ on surface $S$, we will associate it with a $\mathbb{Q}$-submodule of $\mathbb{R}$, denoted by $A(S,\phi)$. $A(S,\phi)$ is defined by an interaction between the Thurston norm and dilatation of pseudo-Anosov…

Geometric Topology · Mathematics 2015-06-12 Hongbin Sun

This article gives the construction and complete classification of all three-dimensional spherical manifolds, and orders them by decreasing volume, in the context of multiconnected universe models with positive spatial curvature. It…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Evelise Gausmann , Roland Lehoucq , Jean-Pierre Luminet , Jean-Philippe Uzan , Jeffrey Weeks

Let $f: S^2 \to S^2$ be a postcritically finite branched covering map without periodic branch points. We give necessary and sufficient algebraic conditions for $f$ to be homotopic, relative to its postcritical set, to an expanding map $g$.

Dynamical Systems · Mathematics 2013-02-11 Peter Haïssinsky , Kevin Pilgrim

We are concerned with orderable groups and particularly those with orderings invariant not only under multiplication, but also under a given automorphism or family of automorphisms. Several applications to topology are given: we prove that…

Group Theory · Mathematics 2014-10-01 Dale Rolfsen , Bert Wiest

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

We construct algorithms and topological invariants that allow us to distinguish the topological type of a surface, as well as functions and vector fields for their topological equivalence. In the first part we discus the main structures…

Dynamical Systems · Mathematics 2025-01-28 Alexandr Prishlyak

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

Nonparametric extension of tensor regression is proposed. Nonlinearity in a high-dimensional tensor space is broken into simple local functions by incorporating low-rank tensor decomposition. Compared to naive nonparametric approaches, our…

Machine Learning · Statistics 2016-03-09 Masaaki Imaizumi , Kohei Hayashi

In this paper, we prove that the self-dual morphological hierarchical structure computed on a n-D gray-level wellcomposed image u by the algorithm of G{\'e}raud et al. [1] is exactly the mathematical structure defined to be the tree of…

Discrete Mathematics · Computer Science 2022-06-13 Thierry GÉraud , Nicolas Boutry , Sébastien Crozet , Edwin Carlinet , Laurent Najman

This final degree project is devoted to study the topological classification of complex plane curves. These are subsets of $\mathbb{C}^2$ that can be described by an equation $f(x,y)=0$. Loosely speaking, curves are said to be equivalent in…

Algebraic Geometry · Mathematics 2024-02-22 Alberto Fernández-Hernández

Natural and man-made transport webs are frequently dominated by dense sets of nested cycles. The architecture of these networks, as defined by the topology and edge weights, determines how efficiently the networks perform their function.…

Quantitative Methods · Quantitative Biology 2016-07-27 Carl D. Modes , Marcelo O. Magnasco , Eleni Katifori

Every finite graph $G$ can be decomposed in a canonical way that displays its local connectivity-structure [DJKK26]. These decompositions are defined via a suitable more tree-like covering of $G$, whose tangle-tree structure is projected…

Combinatorics · Mathematics 2026-03-20 Raphael W. Jacobs , Paul Knappe , Jan Kurkofka

We introduce new types of local algorithms, which we call "ASI Algorithms", and use them to demonstrate a link between descriptive and computable combinatorics. This allows us to unify arguments from the two fields, and also sometimes to…

Logic · Mathematics 2022-06-20 Long Qian , Felix Weilacher

We investigate the combinatorial and dynamical properties of so-called nearly Euclidean Thurston maps, or NET maps. These maps are perturbations of many-to-one folding maps of an affine two-sphere to itself. The close relationship between…

Dynamical Systems · Mathematics 2017-08-24 William Floyd , Gregory Kelsey , Sarah Koch , Russell Lodge , Walter Parry , Kevin M. Pilgrim , Edgar Saenz

We use orbifold structures to deduce degeneracy statements for holomorphic maps into logarithmic surfaces. We improve former results in the smooth case and generalize them to singular pairs. In particular, we give applications on nodal…

Algebraic Geometry · Mathematics 2009-03-18 Erwan Rousseau

Representing a scanned map of the real environment as a topological structure is an important research topic in robotics. Since topological representations of maps save a huge amount of map storage space and online computing time, they are…

Robotics · Computer Science 2019-10-03 Jiawei Hou , Yijun Yuan , Sören Schwertfeger

In this paper we are interested in decomposing a dihypergraph $\mathcal{H} = (V, \mathcal{E})$ into simpler dihypergraphs, that can be handled more efficiently. We study the properties of dihypergraphs that can be hierarchically decomposed…

Discrete Mathematics · Computer Science 2020-06-23 Lhouari Nourine , Simon Vilmin

In this paper we initiate the study of tropical Voronoi diagrams. We start out with investigating bisectors of finitely many points with respect to arbitrary polyhedral norms. For this more general scenario we show that bisectors of three…

Combinatorics · Mathematics 2021-11-05 Francisco Criado , Michael Joswig , Francisco Santos