3 papers
math.CO2020
Combinatorics of intervals in the plane I: trapezoids
Daniel Di Benedetto, Jozsef Solymosi, Ethan White
We study arrangements of intervals in for which many pairs form trapezoids. We show that any set of intervals forming many trapezoids must have underlying algebraic…
math.NT2020
New estimates for exponential sums over multiplicative subgroups and intervals in prime fields
Daniel di Benedetto, Moubariz Z. Garaev, Víctor C. García +3
Let be a multiplicative subgroup of of order . We show that $$ \max_{(a,p)=1}\left|\sum_{x\in {\mathcal H}} {\mathbf{\,e}}_p(ax)\right| \…
math.CO2020
On the directions determined by a Cartesian product in an affine Galois plane
Daniel Di Benedetto, Jozsef Solymosi, Ethan P. White
We prove that the number of directions contained in a set of the form , where is prime, is at least . Here and …