Marta Bielinska : 'Prolegomenon to an epistemology of orbifolds'
Abstract: In general relativity, spacetime is usually taken to be a (3+1)-dimensional Lorentzian manifold that is Hausdorff, paracompact, time-orientable, and so on. However, it seems that there are currently no known experiments that directly test all these spacetime properties. This raises the question of whether it is possible for our spacetime to have a different structure--for example, that of an orbifold, which is, roughly, a manifold quotiented by some group. In our talk, we will address two questions. First, is it possible to empirically verify whether one lives on a manifold or on an orbifold? Second, following up on Read and Bielińska (2022), can one identify the specific type of orbifold on which one is living; for example, is it globally or locally orientable? Our considerations begin with an examination of the topological and differentiable structures of orbifolds. We then discuss the possibility of defining field theories, such as general relativity or quantum field theory, on orbifolds. Finally, we conclude with broader philosophical reflections on epistemology of orbifolds. (Based on joint work with James Read.)
The PoP-grunch (Philosophy of Physics Graduate Lunch) is a weekly informal seminar in which graduate students in Philosophy of Physics present their work in progress.
Philosophy of Physics Graduate Lunch Seminar Convenor: Eleanor March
