5–9 Dec 2022
Australia/Sydney timezone

De Sitter space as coherent state of gravitons

5 Dec 2022, 16:30
20m
149 (Old Main Building)

149

Old Main Building

Inflation and early Universe cosmology Early Universe

Speaker

Dr Otari Sakhelashvili (The University of Sydney)

Description

Not a long ago, it was argued that the quantum gravity only tolerates de Sitter as a state on top of a valid vacuum. So, we construct the de Sitter state as a coherent state of gravitons on top of the Minkowski vacuum. To make the construction consistent, we use BRST quantization. As an example, first we study such construction in QED, and then we generalise it in linear gravity. Coupling the gravity with large number of soft scalars give us possibility to take double-scale, so-called species limit, in which gravity linearize and the construction is exact. In this theory, only collective quantum phenomena, like Gibbons-Hawking radiation, survive. We also double-check consistency of our construction using the above processes.

Author

Dr Otari Sakhelashvili (The University of Sydney)

Presentation materials