English
Related papers

Related papers: Counting Lattice Triangulations

200 papers

Flip graphs were recently introduced in order to discover new matrix multiplication methods for matrix sizes. The technique applies to other tensors as well. In this paper, we explore how it performs for polynomial multiplication.

Symbolic Computation · Computer Science 2025-02-11 Shaoshi Chen , Manuel Kauers

We consider the problem of computing a triangulation of the real projective plane P2, given a finite point set S={p1, p2,..., pn} as input. We prove that a triangulation of P2 always exists if at least six points in S are in general…

Computational Geometry · Computer Science 2011-11-10 Mridul Aanjaneya , Monique Teillaud

We prove an O(log n) bound for the expected value of the logarithm of the componentwise (and, a fortiori, the mixed) condition number of a random sparse n x n matrix. As a consequence, small bounds on the average loss of accuracy for…

Numerical Analysis · Mathematics 2008-07-08 Dennis Cheung , Felipe Cucker

We develop a new, powerful method for counting elements in a multiset. As a first application, we use this algorithm to study the number of occurrences of patterns in a permutation. For patterns of length 3 there are two Wilf classes, and…

Combinatorics · Mathematics 2024-03-05 Andrew R Conway , Anthony J Guttmann

We study the problem of finding a triangulation T of a planar point set S such as to minimize the expected distance between two points x and y chosen uniformly at random from S. By distance we mean the length of the shortest path between x…

Computational Geometry · Computer Science 2012-06-21 Laszlo Kozma

In the unidimensional unfolding model, given m objects in general position there arise 1+m(m-1)/2 rankings. The set of rankings is called the ranking pattern of the m given objects. By changing these m objects, we can generate various…

Combinatorics · Mathematics 2007-07-11 H. Kamiya , P. Orlik , A. Takemura , H. Terao

In this survey article, we are interested on minimal triangulations of closed pl manifolds. We present a brief survey on the works done in last 25 years on the following: (i) Finding the minimal number of vertices required to triangulate a…

Geometric Topology · Mathematics 2007-05-23 Basudeb Datta

We revisit the problem of counting the number of copies of a fixed graph in a random graph or multigraph, including the case of constrained degrees. Our approach relies heavily on analytic combinatorics and on the notion of patchwork to…

Let $M(n)$ denote the number of distinct entries in the $n \times n$ multiplication table. The function $M(n)$ has been studied by Erd\H{o}s, Tenenbaum, Ford, and others, but the asymptotic behaviour of $M(n)$ as $n \to \infty$ is not known…

Number Theory · Mathematics 2021-10-20 Richard Brent , Carl Pomerance , David Purdum , Jonathan Webster

We consider random lattice triangulations of $n\times k$ rectangular regions with weight $\lambda^{|\sigma|}$ where $\lambda>0$ is a parameter and $|\sigma|$ denotes the total edge length of the triangulation. When $\lambda\in(0,1)$ and $k$…

Probability · Mathematics 2015-05-25 Pietro Caputo , Fabio Martinelli , Alistair Sinclair , Alexandre Stauffer

Methods were developed in Ref. [1] for constructing reference metrics (and from them differentiable structures) on three-dimensional manifolds with topologies specified by suitable triangulations. This note generalizes those methods by…

General Relativity and Quantum Cosmology · Physics 2024-01-03 Lee Lindblom , Oliver Rinne

It is well known that many problems in interval computation are intractable, which restricts our attempts to solve large problems in reasonable time. This does not mean, however, that all problems are computationally hard. Identifying…

Numerical Analysis · Computer Science 2022-11-07 Milan Hladík

The multigrid methodology is reviewed. By integrating numerical processes at all scales of a problem, it seeks to perform various computational tasks at a cost that rises as slowly as possible as a function of $n$, the number of degrees of…

High Energy Physics - Lattice · Physics 2009-10-22 Achi Brandt

In this report we present an algorithm solving Triangle Counting in time $O(d^2n+m)$, where n and m, respectively, denote the number of vertices and edges of a graph G and d denotes its twin-width, a recently introduced graph parameter. We…

Data Structures and Algorithms · Computer Science 2022-02-15 Stefan Kratsch , Florian Nelles , Alexandre Simon

We consider tilings of a rectangle which is n units wide and m units long by non-overlapping 1 X 1 squares and s X s squares. Bivariate generating functions are computed with the Transfer Matrix Method for moderately large but fixed widths…

Combinatorics · Mathematics 2016-09-14 Richard J. Mathar

In this paper, we study a family of lattice walks which are related to the Hadamard conjecture. There is a bijection between paths of these walks which originate and terminate at the origin and equivalence classes of partial Hadamard…

Probability · Mathematics 2010-03-23 Warwick de Launey , David A. Levin

We perform a smoothed analysis of the componentwise condition numbers for determinant computation, matrix inversion, and linear equations solving for sparse n times n matrices. The bounds we obtain for the ex- pectations of the logarithm of…

Numerical Analysis · Mathematics 2013-02-26 Dennis Cheung , Felipe Cucker

Triangle strips have been widely used for efficient rendering. It is NP-complete to test whether a given triangulated model can be represented as a single triangle strip, so many heuristics have been proposed to partition models into few…

Computational Geometry · Computer Science 2007-05-23 M. Gopi , David Eppstein

By generalising the notion of a unimodular sequence, we create an expression for the winding number of certain ordered sets of lattice points. Since the winding number of the vertices of a Fano polygon is necessarily one, we use this…

Combinatorics · Mathematics 2019-01-31 Daniel Cavey , Akihiro Higashitani

The problem of counting the different ways of folding the planar triangular lattice is shown to be equivalent to that of counting the possible 3-colorings of its bonds, a dual version of the 3-coloring problem of the hexagonal lattice…

Condensed Matter · Physics 2015-06-25 P. Di Francesco , E. Guitter