Self-dual maps III: Projective links

Abstract

In this paper, we present necessary and sufficient combinatorial conditions for a link to be projective, that is, a link in [Formula: see text]. This characterization is closely related to the notions of antipodally self-dual and antipodally symmetric maps. We also discuss the notion of symmetric cycle, an interesting issue arising in projective links leading us to an easy necessary condition for alternating anti-inversely symmetric links.