Lisa Glaser, Radboud University, Niederlande
In causal set theory space-time is described as a partially ordered set. While this makes identifying geometric properties a little more cumbersome, it does provide a Lorentz invariant discretisation. One interesting side effect of this discretisation are non-local effects in field theories that could be searched for in experiments. One example of such a discreteness effect is a possible mechanism to generate a cosmological constant.
Another feature of this discrete description is that we can use computer simulations to explore the path integral over geometries. In this lecture I will introduce the basic set up of causal set theory, tell you a little bit about non-local signatures and then show some results of computer simulations.