Date:
16. December 2016 - 11:30
Speaker:
Martin Sloth (University of Southern Denmark). Invited by Antonio Riotto.
Soft gravitons produced by the expansion of de Sitter can be viewed as the Nambu-Goldstone bosons of spontaneously broken asymptotic symmetries of the de Sitter spacetime. We explicitly construct the associated charges, and show that acting with the charges on the vacuum creates a new state equivalent to a change in the local coordinates induced by the soft graviton. We then discuss how infrared effects in de Sitter and inflationary spacetimes and be reformulated in terms of this new state. We also make comparisons with a related discussion of black hole evaporation