A nonmanifold theory of space–time

A Zeeman topology is defined in the general framework of any set W of events which has been equipped with an acyclic signal relation ∼ →. The Wssumption that the ∼ → structure of W is locally that of Minkowski space and that the ’’piecing together’’ maps are smooth in an appropriate sense, allows a tangent bundle p:E→W to be defined. This bundle has, as structure group, the group G of linear causal automorphisms of Minkowski space.