SMuK 2023 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

GR: Fachverband Gravitation und Relativitätstheorie

GR 10: Foundations and Alternatives II

GR 10.1: Talk

Wednesday, March 22, 2023, 16:00–16:20, ZEU/0255

The assumption of a continuous Lorentzian spacetime manifold in quantum gravity — •René Friedrich — Strasbourg

Spacetime is more and more often suspected of being at the origin of the problem of quantum gravity, and it is said that the concept of spacetime needs to be revised.

In this talk, we want to provide the concrete reason why the Lorentzian spacetime manifold is not compatible with quantum gravity, by showing that it is a man-made artefact: unlike the Euclidean metric, no Lorentzian pseudometric is able to span up a real-valued manifold. This is why - since its introduction with Minkowski's famous lecture "Space and time" and until today - Lorentzian manifolds require always the addition of a second metric in order to override the appearance of negative squares and of imaginary values.

This artificial "patchwork" of two opposite metrics is not only incompatible with quantum mechanics, it is even contradicting the very principles of general relativity.