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Related papers: Local Differences Determined by Convex sets

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We investigate additive properties of sets $A,$ where $A=\{a_1,a_2,\ldots ,a_k\}$ is a monotone increasing set of real numbers, and the differences of consecutive elements are all distinct. It is known that $|A+B|\geq c|A||B|^{1/2}$ for any…

Combinatorics · Mathematics 2021-07-01 Imre Ruzsa , Jozsef Solymosi

We construct finite sets of real numbers that have a small difference set and strong local properties. In particular, we construct a set $A$ of $n$ real numbers such that $|A-A|=n^{\log_2 3}$ and that every subset $A'\subseteq A$ of size…

Combinatorics · Mathematics 2018-12-27 Sara Fish , Ben Lund , Adam Sheffer

We prove bounds for the number of solutions to $$a_1 + \dots + a_k = a_1' + \dots + a_k'$$ over $N$-element sets of reals, which are sufficiently convex or near-convex. A near-convex set will be the image of a set with small additive…

Number Theory · Mathematics 2021-04-26 Peter J. Bradshaw , Brandon Hanson , Misha Rudnev

Given a subset of real numbers $A$ with small product $AA$ we obtain a new upper bound for the additive energy of $A$. The proof uses a natural observation that level sets of convolutions of the characteristic function of $A$ have small…

Combinatorics · Mathematics 2019-11-28 Konstantin I. Olmezov , Aliaksei S. Semchankau , Ilya D. Shkredov

Finite unions of convex sets are a central object of study in discrete and computational geometry. In this paper we initiate a systematic study of complements of such unions -- i.e., sets of the form $S=\mathbb{R}^d \setminus (\cup_{i=1}^n…

Combinatorics · Mathematics 2025-08-28 Chaya Keller , Micha A. Perles

Let $\mathcal{P}$ be a set of points in the plane, and $\mathcal{S}$ a strictly convex set of points. In this note, we show that if $\mathcal{P}$ contains many translates of $\mathcal{S}$, then these translates must come from a generalized…

Combinatorics · Mathematics 2023-02-28 Gabriel Currier , Jozsef Solymosi , Ethan Patrick White

It is well known that any measure in S^2 satisfying certain simple conditions is the surface measure of a bounded convex body in R^3. It is also known that a local perturbation of the surface measure may lead to a nonlocal perturbation of…

Metric Geometry · Mathematics 2018-06-14 Alexander Plakhov

This article is an exposition of recent results on self-similar sets, asserting that if the dimension is smaller than the trivial upper bound then there are almost overlaps between cylinders. We give a heuristic derivation of the theorem…

Classical Analysis and ODEs · Mathematics 2014-09-30 Michael Hochman

The convexity number of a set $X \subset \mathbb{R}^2$ is the minimum number of convex subsets required to cover it. We study the following question: what is the largest possible convexity number $f(n)$ of $\mathbb{R}^2 \setminus S$, where…

Combinatorics · Mathematics 2026-01-05 Chaya Keller , Micha A. Perles

Large deviation estimates are by now a standard tool inthe Asymptotic Convex Geometry, contrary to small deviationresults. In this note we present a novel application of a smalldeviations inequality to a problem related to the diameters of…

Functional Analysis · Mathematics 2016-12-23 Bo'az Klartag , Roman Vershynin

In several recent papers some concepts of convex analysis were extended to discrete sets. This paper is one more step in this direction. It is well known that a local minimum of a convex function is always its global minimum. We study some…

Combinatorics · Mathematics 2024-02-05 Vladimir Gurvich , Mariya Naumova

Many problems in high-dimensional statistics and optimization involve minimization over nonconvex constraints-for instance, a rank constraint for a matrix estimation problem-but little is known about the theoretical properties of such…

Optimization and Control · Mathematics 2017-10-20 Rina Foygel Barber , Wooseok Ha

We derive several new bounds for the problem of difference sets with local properties, such as establishing the super-linear threshold of the problem. For our proofs, we develop several new tools, including a variant of higher moment…

Combinatorics · Mathematics 2022-08-24 Anqi Li

We present a necessary and sufficient condition for the reachable set, i.e., the set of states reachable from a ball of initial states at some time, of an ordinary differential equation to be convex. In particular, convexity is guaranteed…

Optimization and Control · Mathematics 2013-03-01 Gunther Reißig

We prove a lower bound on the number of the convex components of a compact set with non-empty interior in $\mathbb{R}^n$ for all $n\ge2$. Our result generalizes and improves the inequalities previously obtained in M. Carozza, F. Giannetti,…

Metric Geometry · Mathematics 2023-09-07 Flavia Giannetti , Giorgio Stefani

We introduce the theory of div point sets, which aims to provide a framework to study the combinatoric nature of any set of points in general position on an Euclidean plane. We then show that proving the unsatisfiability of some first-order…

Combinatorics · Mathematics 2019-09-02 Archy Will He

A finite set $S \subset \mathbb{Z}$ is a Sidon set if its pairwise differences are distinct. Recall that a perfect difference set (PDS) of order $n$ is a set $B \subset \mathbb{Z}_v$ ($v = n^2 - n + 1$) of size $n$ such that every nonzero…

Combinatorics · Mathematics 2026-05-15 Tong Niu

We study the first mixed volume for nonconvex sets and apply the results to limits of discrete isoperimetric problems. Let $ M,N \subset \mathbb{R}^d$. Define $D_N (M)=\lim_{\epsilon \downarrow 0} \frac{|M+\epsilon N|-|M|}{\epsilon}$…

Metric Geometry · Mathematics 2016-07-27 Emmanuel Tsukerman

Properties of several sorts of lattices of convex subsets of R^n are examined. The lattice of convex sets containing the origin turns out, for n>1, to satisfy a set of identities strictly between those of the lattice of all convex subsets…

Metric Geometry · Mathematics 2007-06-13 George M. Bergman

We prove that finite sets of real numbers satisfying $|AA| \leq |A|^{1+\epsilon}$ with sufficiently small $\epsilon > 0$ cannot have small additive bases nor can they be written as a set of sums $B+C$ with $|B|, |C| \geq 2$. The result can…

Number Theory · Mathematics 2016-11-22 Ilya D. Shkredov , Dmitrii Zhelezov
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