# Space and Time in a Lorentzian path integral

### APA

Dittrich, B. (2021). Space and Time in a Lorentzian path integral. Perimeter Institute. https://pirsa.org/21060095

### MLA

Dittrich, Bianca. Space and Time in a Lorentzian path integral. Perimeter Institute, Jun. 15, 2021, https://pirsa.org/21060095

### BibTex

@misc{ pirsa_PIRSA:21060095, doi = {10.48660/21060095}, url = {https://pirsa.org/21060095}, author = {Dittrich, Bianca}, keywords = {Quantum Foundations}, language = {en}, title = {Space and Time in a Lorentzian path integral}, publisher = {Perimeter Institute}, year = {2021}, month = {jun}, note = {PIRSA:21060095 see, \url{https://pirsa.org}} }

Perimeter Institute for Theoretical Physics

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Talk Type

**Subject**

Abstract

I will present a quantum gravity approach based on a Lorentzian path integral for quantum geometries. The properties of quantum space time can be measured using geometric operators. This allows also to discuss fluctuations of causal structure as well as violations of (micro-) causality. I will explain how the Lorentzian path integral comes with various options regarding which quantum space times to sum over: e.g. whether to include causality violations or not, or whether to allow also for space times with Euclidean signatures in Lorentzian path integrals. I will sketch some consequences for the resulting theories.