Inflationary flavor oscillations and the cosmic spectroscopy

Pinol, Lucas; Aoki, Shuntaro; Renaux‐Petel, Sébastien; Yamaguchi, Masahide

doi:10.1103/physrevd.107.l021301

Cited by 26 publications

(25 citation statements)

References 41 publications

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“…Strong mixing and modified dispersion relation. We will see in section 3 that in the strong mixing regime, the quadratic theory is dominated by the mixing term and one can realise that (2.6) can be reduced to an effective single-field theory with non-linear dispersion relation for the Goldstone boson [48,51,55]. It is then easy to obtain the following bounds…”

Section: Jcap12(2023)035mentioning

confidence: 96%

“…We show that all correlators, including the (would-be) doubleand triple-exchange diagrams, are obtained by acting with weight-shifting operators on a set of seed correlators. At strong mixing, we use the recently developed cosmological flow approach [39,48] to numerically compute these correlators. In section 5, we present an indepth analysis of the low-speed collider phenonenology, paying particular attention to its strong mixing regime.…”

Section: Jcap12(2023)035mentioning

confidence: 99%

“…Here, we give bounds on these couplings based on perturbativity, at weak and strong mixing. We will give additional details on these regimes in section 3, and refer to [48] for a detailed analysis (see also [53,54] for methods to derive perturbativity bounds). We also comment on theoretically motivated values for the mass of the heavy field.…”

Section: Perturbativity Bounds On Couplingsmentioning

confidence: 99%

“…Indeed, if the additional field is light and weakly mixed to π c , the Goldstone boson is continuously sourced by σ on super-Hubble scales. The dynamics is then sensitive to the amount of efolds elapsed from the moment at which the mode crosses the horizon to the end of inflation (see [48] for an exhaustive analysis of the full parameter space). In the next section, we derive the precise regime of validity of the non-local single-field theory (3.6).…”

Section: Modified Dispersion Relationmentioning

confidence: 99%

“…After quantizing the theory and imposing Bunch-Davis initial conditions, the mode functions are completely determined in term of the Hankel function (see [48,51] for more details)…”

Section: Modified Dispersion Relationmentioning

confidence: 99%

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Shapes of the cosmological low-speed collider

Jazayeri,

Renaux-Petel,

Werth

2023

J. Cosmol. Astropart. Phys.

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Massive particles produced during inflation leave specific signatures in soft limits of correlation functions of primordial fluctuations. When the Goldstone boson of broken time translations acquires a reduced speed of sound, implying that de Sitter boosts are strongly broken, we introduce a novel discovery channel to detect new physics during inflation, called the cosmological low-speed collider signal. This signal is characterised by a distinctive resonance lying in mildly-soft kinematic configurations of cosmological correlators, indicating the presence of a heavy particle, whose position enables to reconstruct its mass. We show that this resonance can be understood in terms of a non-local single-field effective field theory, in which the heavy field becomes effectively non-dynamical. This theory accurately describes the full dynamics of the Goldstone boson and captures all multi-field physical effects distinct from the non-perturbative particle production leading to the conventional cosmological collider signal. As such, this theory provides a systematic and tractable way to study the imprint of massive fields on cosmological correlators. We conduct a thorough study of the low-speed collider phenomenology in the scalar bispectrum, showing that large non-Gaussianities with new shapes can be generated, in particular beyond weak mixing. We also provide a low-speed collider template for future cosmological surveys.

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Section: Jcap12(2023)035mentioning

confidence: 96%

Section: Jcap12(2023)035mentioning

confidence: 99%

Section: Perturbativity Bounds On Couplingsmentioning

confidence: 99%

Section: Modified Dispersion Relationmentioning

confidence: 99%

“…After quantizing the theory and imposing Bunch-Davis initial conditions, the mode functions are completely determined in term of the Hankel function (see [48,51] for more details)…”

Section: Modified Dispersion Relationmentioning

confidence: 99%

See 3 more Smart Citations

Shapes of the cosmological low-speed collider

Jazayeri,

Renaux-Petel,

Werth

2023

J. Cosmol. Astropart. Phys.

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Nonanalyticity and on-shell factorization of inflation correlators at all loop orders

Qin,

Xianyu

2024

J. High Energ. Phys.

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The dynamics of quantum fields during cosmic inflation can be probed via their late-time boundary correlators. The analytic structure of these boundary correlators contains rich physical information of bulk dynamics, and is also closely related to cosmological collider observables. In this work, we study a particular type of nonanalytic behavior, called nonlocal signals, for inflation correlators with massive exchanges at arbitrary loop orders. We propose a signal-detection algorithm to identify all possible sources of nonlocal signals in an arbitrary loop graph, and prove that the algorithm is exhaustive. We then present several versions of the on-shell factorization theorem for the leading nonlocal signal in graphs with arbitrary number of loops, and provide the explicit analytical expression for the leading nonlocal signal. We also generalize the nonlocal-signal cutting rule to arbitrary loop graphs. Finally, we provide many explicit examples to demonstrate the use of our results, including an n-loop melon graph and a variety of 2-loop graphs.

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Inflation correlators with multiple massive exchanges

Xianyu,

Zang

2024

J. High Energ. Phys.

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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.

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Inflationary flavor oscillations and the cosmic spectroscopy

Cited by 26 publications

References 41 publications

Shapes of the cosmological low-speed collider

Shapes of the cosmological low-speed collider

Nonanalyticity and on-shell factorization of inflation correlators at all loop orders

Inflation correlators with multiple massive exchanges

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