An improved lower bound related to the Furstenberg-Sárközy theorem
The electronic journal of combinatorics, Tome 22 (2015) no. 1
Let $D(n)$ denote the cardinality of the largest subset of the set $\{1,2,\ldots,n\}$ such that the difference of no pair of distinct elements is a square. A well-known theorem of Furstenberg and Sárközy states that $D(n)=o(n)$. In the other direction, Ruzsa has proven that $D(n) \gtrsim n^{\gamma}$ for $\gamma = \frac{1}{2}\left( 1 + \frac{\log 7}{\log 65} \right) \approx 0.733077$. We improve this to $\gamma = \frac{1}{2}\left( 1 + \frac{\log 12}{\log 205} \right) \approx 0.733412$.
DOI :
10.37236/4656
Classification :
05D10, 05B10
Mots-clés : Ramsey theory, squares, difference set
Mots-clés : Ramsey theory, squares, difference set
Affiliations des auteurs :
Mark Lewko  1
@article{10_37236_4656,
author = {Mark Lewko},
title = {An improved lower bound related to the {Furstenberg-S\'ark\"ozy} theorem},
journal = {The electronic journal of combinatorics},
year = {2015},
volume = {22},
number = {1},
doi = {10.37236/4656},
zbl = {1307.05219},
url = {http://geodesic.mathdoc.fr/articles/10.37236/4656/}
}
Mark Lewko. An improved lower bound related to the Furstenberg-Sárközy theorem. The electronic journal of combinatorics, Tome 22 (2015) no. 1. doi: 10.37236/4656
Cité par Sources :