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We prove existence and uniqueness of the minimizer for the average geodesic distance to the points of a geodesically convex set on the sphere. This implies a corresponding existence and uniqueness result for an optimal algorithm for…

Machine Learning · Computer Science 2008-05-16 Andreas Maurer

Using the notion of Dubiner distance, we give an elementary proof of the fact that good covering point configurations on the 2-sphere are optimal polynomial meshes. From these we extract Caratheodory-Tchakaloff (CATCH) submeshes for…

Numerical Analysis · Mathematics 2016-12-16 Paul Leopardi , Alvise Sommariva , Marco Vianello

A cap of spherical radius $\alpha$ on a unit $d$-sphere $S$ is the set of points within spherical distance $\alpha$ from a given point on the sphere. Let $\mathcal F$ be a finite set of caps lying on $S$. We prove that if no hyperplane…

Metric Geometry · Mathematics 2022-08-10 Alexandr Polyanskii

Let S be a triangulated 2-sphere with fixed triangulation T. We apply the methods of thin position from knot theory to obtain a simple version of the three geodesics theorem for the 2-sphere [5]. In general these three geodesics may be…

Geometric Topology · Mathematics 2014-09-11 Abigail Thompson

Let $X$ be a smooth projective algebraic variety over a number field $k$ and $P$ in $X(k)$. In 2007, the second author conjectured that, in a precise sense, if rational points on $X$ are dense enough, then the best rational approximations…

Algebraic Geometry · Mathematics 2024-03-06 Brian Lehmann , David McKinnon , Matthew Satriano

Optimal packing of spheres in $\mathbb R^d$ is studied by optimization of the energy $E$ (effective conductivity) of composites with ideally conducting spherical inclusions. It is demonstrated that the minimum of $E$ over locations of…

Metric Geometry · Mathematics 2014-12-25 Vladimir Mityushev

In this paper we investigate the Erd\"os/Falconer distance conjecture for a natural class of sets statistically, though not necessarily arithmetically, similar to a lattice. We prove a good upper bound for spherical means that have been…

Classical Analysis and ODEs · Mathematics 2007-05-23 Alex Iosevich , Misha Rudnev

Define the tet-volume of a triangulation of the 2-sphere to be the minimum number of tetrahedra in a 3-complex of which it is the boundary, and let $d(v)$ be the maximum tet-volume for $v$-vertex triangulations. In 1986 Sleator, Tarjan, and…

Combinatorics · Mathematics 2025-05-20 Peter Doyle , Matthew Ellison , Zili Wang

It is shown here how prior estimates on the local shape of the universe can be used to reduce, to a small region, the full parameter space for the search of circles in the sky. This is the first step towards the development of efficient…

Astrophysics · Physics 2007-05-23 G. I. Gomero

The paper concerns the uniform polynomial approximation of a function $f$, continuous on the unit Euclidean sphere of ${\mathbb R}^3$ and known only at a finite number of points that are somehow uniformly distributed on the sphere. First we…

Numerical Analysis · Mathematics 2018-08-10 Woula Themistoclakis , Marc Van Barel

Using a ramified cover of the two-sphere by the torus, we prove a local optimal inequality between the diastole and the area on the two-sphere near a singular metric. This singular metric, made of two equilateral triangles glued along their…

Differential Geometry · Mathematics 2014-10-03 Florent Balacheff

In this paper, we prove the existence of a spherical $t$-design formed by adding extra points to an arbitrarily given point set on the sphere and, subsequently, deduce the existence of nested spherical designs. Estimates on the number of…

Functional Analysis · Mathematics 2024-05-20 Ruigang Zheng , Xiaosheng Zhuang

In this article we investigate the $N$-point min-max and the max-min polarization problems on the sphere for a large class of potentials in $\mathbb{R}^n$. We derive universal lower and upper bounds on the polarization of spherical designs…

Combinatorics · Mathematics 2022-07-20 Peter Boyvalenkov , Peter Dragnev , Douglas Hardin , Edward Saff , Maya Stoyanova

In this paper, we consider a conjecture of Erdos and Rosenfeld and a conjecture of Ruzsa when the number is an almost square. By the same method, we consider lattice points of a circle close to the x-axis with special radii.

Number Theory · Mathematics 2014-06-10 Tsz Ho Chan

We derive an analytical closed expression to compute the minimum distance (quantified by the angle of separation measured from the center of the Earth) between any two satellites located at the same altitude and in circular orbits. We also…

Instrumentation and Methods for Astrophysics · Physics 2020-12-30 Martín Avendaño , David Arnas , Richard Linares , Miles Lifson

We describe a randomized algorithm that, given a set $P$ of points in the plane, computes the best location to insert a new point $p$, such that the Delaunay triangulation of $P\cup\{p\}$ has the largest possible minimum angle. The expected…

Computational Geometry · Computer Science 2014-01-07 Boris Aronov , Mark V. Yagnatinsky

We introduce a convergent finite difference method for solving the optimal transportation problem on the sphere. The method applies to both the traditional squared geodesic cost (arising in mesh generation) and a logarithmic cost (arising…

Numerical Analysis · Mathematics 2021-05-11 Brittany Froese Hamfeldt , Axel G. R. Turnquist

The two dimensional sphere can't be approximated by finite homogeneous spaces. We describe the optimal approximation and its distance from the sphere.

Group Theory · Mathematics 2020-01-14 Omer Lavi

art, Iosevich, Koh and Rudnev (2007) show, using Fourier analysis method, that the finite Erd\"os-Falconer distance conjecture holds for subsets of the unit sphere in $\mathbbm{F}_q^d$. In this note, we give a graph theoretic proof of this…

Combinatorics · Mathematics 2008-10-09 Le Anh Vinh

We study the Erdos distance conjecture on the unit sphere in three dimensions using Fourier analytic methods.

Combinatorics · Mathematics 2007-05-23 Alex Iosevich , Mischa Rudnev