Philosophy of Physics Seminar (Thursday - Week 6, HT25)
Thursday 27th February 3:00pm - 5:00pm
Lecture Room, Radcliffe Humanities
Quentin Vigneron (Nicolaus Copernicus University, Toruń): 'Modifying general relativity on the basis of topological considerations from the Newtonian limit'
Abstract: Cosmic topology is the study of the shape and global curvature of our Universe. While general relativity is defined for any possible topology for ou Universe, classical Newtonian gravitation is only well-defined for a universe with a Euclidean topology. This leads to the following question: can we generalise Newtonian gravitation to any topology? I will show that the answer is YES, which leads to a second question: is general relativity compatible with Newtonian gravitation in any topology possible for our Universe? I will show that the answer is NO. I will argue that this incompatibility asks for a modification of general relativity in order to admit a Newtonian limit in any topology. I will present such a modification in which a non-dynamical term depending on the topology is added in the Einstein equation. Consequences for cosmology, and future prospects will be briefly presented.
