I will give an introduction to Fröhlich's Events, Trees, Histories (ETH) approach to quantum theory. I will then introduce the causal compatibility conjecture. Applying it to spacetimes with closed causal curves we find that time travel is boring. Finally I will introduce the open problem in mathematical relativity underlying the causal compatibility conjecture.
Claudio Paganini (Regensburg): The Causal Compatibility Conjecture and its Implication on Time Travel
