Inflation Correlators with Multiple Massive Exchanges

Fuente: arXiv
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Main Authors: Xianyu, Zhong-Zhi, Zang, Jiaju
Format: Preprint
Published: 2023
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author Xianyu, Zhong-Zhi
Zang, Jiaju
author_facet Xianyu, Zhong-Zhi
Zang, Jiaju
contents The most general tree-level boundary correlation functions of quantum fields in inflationary spacetime involve multiple exchanges of massive states in the bulk, which are technically difficult to compute due to the multi-layer nested time integrals in the Schwinger-Keldysh formalism. On the other hand, correlators with multiple massive exchanges are well motivated in cosmological collider physics, with the original quasi-single-field inflation model as a notable example. In this work, with the partial Mellin-Barnes representation, we derive a simple rule, called family-tree decomposition, for directly writing down analytical answers for arbitrary nested time integrals in terms of multi-variable hypergeometric series. We present the derivation of this rule together with many explicit examples. This result allows us to obtain analytical expressions for general tree-level inflation correlators with multiple massive exchanges. As an example, we present the full analytical results for a range of tree correlators with two massive exchanges.
format Preprint
id arxiv_https___arxiv_org_abs_2309_10849
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Inflation Correlators with Multiple Massive Exchanges
Xianyu, Zhong-Zhi
Zang, Jiaju
High Energy Physics - Theory
Cosmology and Nongalactic Astrophysics
High Energy Physics - Phenomenology
The most general tree-level boundary correlation functions of quantum fields in inflationary spacetime involve multiple exchanges of massive states in the bulk, which are technically difficult to compute due to the multi-layer nested time integrals in the Schwinger-Keldysh formalism. On the other hand, correlators with multiple massive exchanges are well motivated in cosmological collider physics, with the original quasi-single-field inflation model as a notable example. In this work, with the partial Mellin-Barnes representation, we derive a simple rule, called family-tree decomposition, for directly writing down analytical answers for arbitrary nested time integrals in terms of multi-variable hypergeometric series. We present the derivation of this rule together with many explicit examples. This result allows us to obtain analytical expressions for general tree-level inflation correlators with multiple massive exchanges. As an example, we present the full analytical results for a range of tree correlators with two massive exchanges.
title Inflation Correlators with Multiple Massive Exchanges
topic High Energy Physics - Theory
Cosmology and Nongalactic Astrophysics
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2309.10849