Remarks on K3 surfaces with non-symplectic automorphisms of order 7

Abstract

In this note, we treat a pair of a K3 surface and a non-symplectic automorphism of order 7m (m=1, 3 and 6) on it. We show that if the fixed locus of a non-symplectic automorphism order 7 is "special" then the pair is unique up to isomorphism. And we describe fixed loci of non-symplectic automorphisms of order 21 and 42.

This paper has been withdrawn by the author because it turns out that the main result is not true