Automorphisms of elliptic $K3$ surfaces and Salem numbers of maximal degree

Abstract

Using elliptic structures, we show that any supersingular K3 surface of Artin invariant $1$ in characteristic $p\ne 5$, $7$, $13$ has an automorphism the entropy of which is the natural logarithm of a Salem number of degree $22$.

12pages, introduction has been slightly changed and typos are corrected