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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Better Bounds for Planar Sets Avoiding Unit Distances

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Author(s):
Keleti, Tamas [1] ; Matolcsi, Mate [2] ; de Oliveira Filho, Fernando Mario [3] ; Ruzsa, Imre Z. [2]
Total Authors: 4
Affiliation:
[1] Eotvos Lorand Univ, Inst Math, Pazmany P Setany 1-C, H-1117 Budapest - Hungary
[2] Hungarian Acad Sci, Alfred Renyi Inst Math, POB 127, H-1364 Budapest - Hungary
[3] Univ Sao Paulo, Inst Matemat & Estat, Rua Matao 1010, BR-05508090 Sao Paulo, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: DISCRETE & COMPUTATIONAL GEOMETRY; v. 55, n. 3, p. 642-661, APR 2016.
Web of Science Citations: 0
Abstract

A 1-avoiding set is a subset of that does not contain pairs of points at distance 1. Let denote the maximum fraction of that can be covered by a measurable 1-avoiding set. We prove two results. First, we show that any 1-avoiding set in that displays block structure (i.e., is made up of blocks such that the distance between any two points from the same block is less than 1 and points from distinct blocks lie farther than 1 unit of distance apart from each other) has density strictly less than . For the special case of sets with block structure this proves a conjecture of ErdAs asserting that . Second, we use linear programming and harmonic analysis to show that m(1) (R-2) <= 0.258795. (AU)

FAPESP's process: 13/03447-6 - Combinatorial structures, optimization, and algorithms in theoretical Computer Science
Grantee:Carlos Eduardo Ferreira
Support Opportunities: Research Projects - Thematic Grants