Pointless K3 surfaces over finite fields

Abstract

We provide an algorithm for enumerating ordinary K3 surfaces over a fixed finite field based on Taelman's theorem. We use this algorithm to prove that there exist no K3 surfaces without rational points over $\mathbb{F}_q$ for every prime power $q\geq 13$. For elliptic K3 surfaces, we give a geometric proof of this non-existence without computer assistance. On the other hand, we also provide explicit pointless K3 surfaces over $\mathbb{F}_q$ for every prime power $q\leq 11$.