IBS/KAIST Joint Discrete Math Seminar
On strong Sidon sets of integers
Sang June Lee
Duksung Women’s University, Seoul
Duksung Women’s University, Seoul
2019/05/08 Wed 4:30PM-5:30PM (IBS, Room B232)
Let N be the set of natural numbers. A set A⊂N is called a Sidon set if the sums a1+a2, with a1,a2∈S and a1≤a2, are distinct, or equivalently, if
|(x+w)−(y+z)|≥1
for every x,y,z,w∈S with x<y≤z<w. We define strong Sidon sets as follows:</p>
|(x+w)−(y+z)|≥1
for every x,y,z,w∈S with x<y≤z<w. We define strong Sidon sets as follows:</p>
For a constant α with 0≤α<1, a set S⊂N is called an α-strong Sidon set if
|(x+w)−(y+z)|≥wα
for every x,y,z,w∈S with x<y≤z<w.
The motivation of strong Sidon sets is that a strong Sidon set generates many Sidon sets by altering each element a bit. This infers that a dense strong Sidon set will guarantee a dense Sidon set contained in a sparse random subset of N.
In this talk, we are interested in how dense a strong Sidon set can be. This is joint work with Yoshiharu Kohayakawa, Carlos Gustavo Moreira and Vojtěch Rödl.