Radical Perspectivalism, Locality and Relativity

Perspectivalism is a natural ingredient of unitary one-world quantum mechanics. After briefly reviewing arguments for this thesis, we argue that a radical version of perspectivalism is able to provide local and relativistically covariant accounts of physical processes, and thus offers a way out of several no-go theorems. According to this radical perspectivalism, different perspectives are independent of each other and remain so even when they make causal contact. This leads to a worldview that is highly counter-intuitive, but does not lead to conflicts with experience. Moreover, locality and compatibility with relativity theory are positive points of radical perspectivalism.