Asymptotic symmetries in de Sitter and inflationary spacetimes

Journal Article · Sat Apr 01 04:00:00 EDT 2017 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2017/04/033· OSTI ID:22679909

Ferreira, Ricardo Z.; Sandora, McCullen

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. While the effect remains unobservable within the domain of a single observer where the symmetry is unbroken, this change is physical when comparing different asymptotic observers, or between a transformed and un-transformed initial state, consistent with the scale-dependent statistical anisotropies previously derived using semiclassical relations. We then compute the overlap, (0| 0'), between the unperturbed de Sitter vacuum |0), and the state | 0') obtained by acting N times with the charge. We show that when N→ M {sub p} {sup 2}/ H {sup 2} this overlap receives order one corrections and 0(0| 0')→ , which corresponds to an infrared perturbative breakdown after a time t {sub dS} ∼ M {sub p} {sup 2}/ H {sup 3} has elapsed, consistent with earlier arguments in the literature arguing for a perturbative breakdown on this timescale. We also discuss the generalization to inflation, and rederive the 3-point and one-loop consistency relations.

• OSTI ID: 22679909
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 04 Vol. 2017; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANISOTROPY
ASYMPTOTIC SOLUTIONS
BREAKDOWN
COMPARATIVE EVALUATIONS
D S MESONS
DE SITTER SPACE
EXPANSION
GOLDSTONE BOSONS
GRAVITONS
INFLATIONARY UNIVERSE
SEMICLASSICAL APPROXIMATION
SPACE-TIME
SYMMETRY BREAKING