TAU Combinatorics Seminar 2022/23

When: Sunday, December 11, 10am
Where: Schreiber 309
Speaker: Shoham Letzter, University College London
Title: Separating path systems of almost linear size


A separating path system for a graph $G$ is a collection $\mathcal{P}$ of paths in $G$ such that for every two edges $e$ and $f$ in $G$, there is a path in $\mathcal{P}$ that contains $e$ but not $f$. We show that every $n$-vertex graph has a separating path system of size $O(n \log^* n)$. This improves upon the previous best upper bound of $O(n \log n)$, and makes progress towards a conjecture of Falgas-Ravry-Kittipassorn-Korándi-Letzter-Narayanan and Balogh-Csaba-Martin-Pluhár, according to which an $O(n)$ bound should hold.