Title
ON THE DIRECTIONS DETERMINED BY A CARTESIAN PRODUCT IN AN AFFINE GALOIS PLANE
Abstract
We prove that the number of directions contained in a set of the form AxB subset of AG(2,p), where p is prime, is at least vertical bar A vertical bar vertical bar B vertical bar-min{vertical bar A vertical bar; vertical bar B vertical bar}+2. Here A and B are subsets of GF (p) each with at least two elements and vertical bar A vertical bar vertical bar B vertical bar<p. This bound is tight for an infinite class of examples. Our main tool is the use of the Redei polynomial with Szonyi's extension. As an application of our main result, we obtain an upper bound on the clique number of a Paley graph, matching the current best bound obtained recently by Hanson and Petridis.
Year
DOI
Venue
2021
10.1007/s00493-020-4516-z
COMBINATORICA
DocType
Volume
Issue
Journal
41
6
ISSN
Citations 
PageRank 
0209-9683
0
0.34
References 
Authors
0
3
Name
Order
Citations
PageRank
Di Benedetto Daniel100.34
Solymosi Jozsef200.34
Ethan P. White353.15