The Källén-Lehmann representation in de Sitter spacetime

Fuente: arXiv
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Autori principali: Loparco, Manuel, Penedones, Joao, Vaziri, Kamran Salehi, Sun, Zimo
Natura: Preprint
Pubblicazione: 2023
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author Loparco, Manuel
Penedones, Joao
Vaziri, Kamran Salehi
Sun, Zimo
author_facet Loparco, Manuel
Penedones, Joao
Vaziri, Kamran Salehi
Sun, Zimo
contents We study two-point functions of symmetric traceless local operators in the bulk of de Sitter spacetime. We derive the Källén-Lehmann spectral decomposition for any spin and show that unitarity implies its spectral densities are nonnegative. In addition, we recover the Källén-Lehmann decomposition in Minkowski space by taking the flat space limit. Using harmonic analysis and the Wick rotation to Euclidean Anti de Sitter, we derive an inversion formula to compute the spectral densities. Using the inversion formula, we relate the analytic structure of the spectral densities to the late-time boundary operator content. We apply our technical tools to study two-point functions of composite operators in free and weakly coupled theories. In the weakly coupled case, we show how the Källén-Lehmann decomposition is useful to find the anomalous dimensions of the late-time boundary operators. We also derive the Källén-Lehmann representation of two-point functions of spinning primary operators of a Conformal Field Theory on de Sitter.
format Preprint
id arxiv_https___arxiv_org_abs_2306_00090
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle The Källén-Lehmann representation in de Sitter spacetime
Loparco, Manuel
Penedones, Joao
Vaziri, Kamran Salehi
Sun, Zimo
High Energy Physics - Theory
General Relativity and Quantum Cosmology
We study two-point functions of symmetric traceless local operators in the bulk of de Sitter spacetime. We derive the Källén-Lehmann spectral decomposition for any spin and show that unitarity implies its spectral densities are nonnegative. In addition, we recover the Källén-Lehmann decomposition in Minkowski space by taking the flat space limit. Using harmonic analysis and the Wick rotation to Euclidean Anti de Sitter, we derive an inversion formula to compute the spectral densities. Using the inversion formula, we relate the analytic structure of the spectral densities to the late-time boundary operator content. We apply our technical tools to study two-point functions of composite operators in free and weakly coupled theories. In the weakly coupled case, we show how the Källén-Lehmann decomposition is useful to find the anomalous dimensions of the late-time boundary operators. We also derive the Källén-Lehmann representation of two-point functions of spinning primary operators of a Conformal Field Theory on de Sitter.
title The Källén-Lehmann representation in de Sitter spacetime
topic High Energy Physics - Theory
General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2306.00090