On Minkowskian branching structures

In Belnap's [Branching space-time. Synthese, 92, 385–434. ‘Postprint’ archived at http://philsci-archive.pitt.edu/archive/00001003] theory of branching space-times (BST) Our World's possible histories are thought of as space-times, yet the theory has models in which histories do not resemble relativistic space-times or any other physical space-times. The aim of this paper is to define a certain class of BST models, called ‘Minkowskian Branching Structures’ (MBSs), in which histories are isomorphic to Minkowski space-time. By focusing on these models rather than on general BST models, we hope that one may be able to improve on earlier BST analyses of physical phenomena. Also, introducing MBSs sets the stage for recent discussions about whether or not branching is physically feasible.