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Related papers: Density Frankl-R\"{o}dl on the Sphere

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Let $X$ be any subset of the interval $[-1,1]$. A subset $I$ of the unit sphere in $R^n$ will be called \emph{$X$-avoiding} if $<u,v >\notin X$ for any $u,v \in I$. The problem of determining the maximum surface measure of a $\{ 0…

Combinatorics · Mathematics 2015-02-26 Evan DeCorte , Oleg Pikhurko

For a set of distances D={d_1,...,d_k} a set A is called D-avoiding if no pair of points of A is at distance d_i for some i. We show that the density of A is exponentially small in k provided the ratios d_1/d_2, d_2/d_3, ..., d_{k-1}/d_k…

Combinatorics · Mathematics 2008-02-24 Boris Bukh

Using graph-theoretic methods we give a new proof that for all sufficiently large $n$, there exist sphere packings in $\R^n$ of density at least $cn2^{-n}$, exceeding the classical Minkowski bound by a factor linear in $n$. This matches up…

Combinatorics · Mathematics 2007-05-23 Michael Krivelevich , Simon Litsyn , Alexander Vardy

In this paper we derive new upper bounds for the densities of measurable sets in R^n which avoid a finite set of prescribed distances. The new bounds come from the solution of a linear programming problem. We apply this method to obtain new…

Combinatorics · Mathematics 2010-09-17 Fernando Mario de Oliveira Filho , Frank Vallentin

We prove the first inverse theorem for point--sphere incidence bounds over finite fields in dimensions $d \ge 3$, showing that near-extremality forces algebraic rigidity. While sharp upper bounds have been known for over a decade, the…

Combinatorics · Mathematics 2026-02-12 Shalender Singh , Vishnu Priya Singh

We study generalizations of the Schr\"odinger problem in statistical mechanics in two directions: when the density is constrained at more than two times, and when the joint law of the initial and final positions for the particles is…

Probability · Mathematics 2020-01-30 Aymeric Baradat , Christian Léonard

We show that there exists an absolute constant $c_0<1$ such that for all $n \ge 2$, any measurable set $A \subset S^{n-1}$ of density at least $c_0$ contains $n$ pairwise orthogonal vectors. The result is sharp up to the value of the…

Metric Geometry · Mathematics 2025-06-12 Dmitrii Zakharov

We prove a lower bound on the entropy of sphere packings of $\mathbb R^d$ of density $\Theta(d \cdot 2^{-d})$. The entropy measures how plentiful such packings are, and our result is significantly stronger than the trivial lower bound that…

Probability · Mathematics 2019-12-04 Matthew Jenssen , Felix Joos , Will Perkins

For any $d\in \mathbb{N}$ and any function $f:(0,\infty)\to [0,1]$ with $f(R)\to 0$ as $R\to \infty$, we construct a set $A \subseteq \mathbb{R}^d$ and a sequence $R_n \to \infty$ such that $\|x-y\| \neq R_n$ for all $x,y\in A$ and…

Classical Analysis and ODEs · Mathematics 2019-06-06 Alex Rice

Given a sphere of any radius $r$ in an $n$-dimensional Euclidean space, we study the coverings of this sphere with solid spheres of radius one. Our goal is to design a covering of the lowest covering density, which defines the average…

Metric Geometry · Mathematics 2018-05-22 Ilya Dumer

A new formalism is presented for analytically obtaining the probability density function, \( P_{n}(s) \), for the distance between two random points in an \( n \)-dimensional sphere of radius \( R \). Our formalism allows \( P_{n}(s) \) to…

Mathematical Physics · Physics 2007-05-23 Shu-Ju Tu , Ephraim Fischbach

Questions surrounding the spatial disposition of particles in various condensed-matter systems continue to pose many theoretical challenges. This paper explores the geometric availability of amorphous many-particle configurations that…

Statistical Mechanics · Physics 2007-05-23 S. Torquato , F. H. Stillinger

This paper is the fourth and the last part of the series "Spherical higher order Fourier analysis over finite fields", aiming to develop the higher order Fourier analysis method along spheres over finite fields, and to solve the Geometric…

Number Theory · Mathematics 2024-07-29 Wenbo Sun

We investigate the problem of density estimation on the unit circle and the unit sphere from a computational perspective. Our primary goal is to develop new density estimators that are both rate-optimal and computationally efficient for…

Statistics Theory · Mathematics 2026-05-08 Athanasios G. Georgiadis , Andrew P. Percival

We present Newtonian and fully general-relativistic solutions for the evolution of a spherical region of uniform interior density \rho_i(t), embedded in a background of uniform exterior density \rho_e(t). In both regions, the fluid is…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Roshina Nandra , Anthony Lasenby , Michael Hobson

We investigate the particle and kinetic-energy densities for a system of $N$ fermions bound in a local (mean-field) potential $V(\bfr)$. We generalize a recently developed semiclassical theory [J. Roccia and M. Brack, Phys. Rev.\ Lett. {\bf…

Mathematical Physics · Physics 2015-05-14 J. Roccia , M. Brack , A. Koch

We introduce a model of attractive penetrable spheres by adding a short range attractive square well outside a penetrable core, and we provide a detailed analysis of structural and thermodynamical properties in one dimension using the exact…

Soft Condensed Matter · Physics 2009-09-24 Andres Santos , Riccardo Fantoni , Achille Giacometti

We find necessary and sufficient conditions for a finite $K$-bi-invariant measure on a compact Gelfand pair $(G, K)$ to have a square-integrable density. For convolution semigroups, this is equivalent to having a continuous density in…

Probability · Mathematics 2017-06-05 David Applebaum , Trang Le Ngan

We give a new proof of the Frankl-R\"odl theorem on forbidden intersections, via the probabilistic method of dependent random choice. Our method extends to codes with forbidden distances, where over large alphabets our bound is…

Combinatorics · Mathematics 2014-02-26 Peter Keevash , Eoin Long

Let $S = \{p_1,\dots,p_r\}$ be a finite set of distinct primes, let $\Psi_S(X)$ be the number of $S$-smooth integers not exceeding $X$, and let $F_S(X)$ be the maximum size of a subset of $M(S) \cap [1,X]$ containing no set $\{n,p_1…

Number Theory · Mathematics 2026-04-20 Nikola Veselinov
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