Hamiltonicity of expanders: optimal bounds and applications

Autor: Draganić, Nemanja, Montgomery, Richard, Correia, David Munhá, Pokrovskiy, Alexey, Sudakov, Benny
Rok vydání: 2024
Předmět:
Druh dokumentu: Working Paper
Popis: An $n$-vertex graph $G$ is a $C$-expander if $|N(X)|\geq C|X|$ for every $X\subseteq V(G)$ with $|X|< n/2C$ and there is an edge between every two disjoint sets of at least $n/2C$ vertices. We show that there is some constant $C>0$ for which every $C$-expander is Hamiltonian. In particular, this implies the well known conjecture of Krivelevich and Sudakov from 2003 on Hamilton cycles in $(n,d,\lambda)$-graphs. This completes a long line of research on the Hamiltonicity of sparse graphs, and has many applications, including to the Hamiltonicity of random Cayley graphs.
Databáze: arXiv