Non-Gaussianity as a particle detector

By Hayden Lee, D. Baumann, G. L. Pimentel. Journal of High Energy Physics, 2016

257 citations recorded by the source corpus.

We study the imprints of massive particles with spin on cosmological correlators. Using the framework of the effective field theory of inflation, we classify the couplings of these particles to the Goldstone boson of broken time translations and the graviton. We show that it is possible to generate observable non-Gaussianity within the regime of validity of the effective theory, as long as the masses of the particles are close to the Hubble scale and their interactions break the approximate conformal symmetry of the inflationary background. We derive explicit shape functions for the scalar and tensor bispectra that can serve as templates for future observational searches.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/7b8b1cf64303fe3a298958c4e4b67dbf569ab4fe

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Citations in the corpus

Primordial Non-Gaussianity (2019, unknown): “[95] Hayden Lee, Daniel Baumann, and Guilherme L.”
Bootstrapping inflationary correlators in Mellin space (2019, background): “Non-analytic terms in k ∼ k3, on the other hand, signal the presence of new particles in the inflationary three-point functions [22, 24, 25, 27, 29, 30, 47, 48, 131, 132].”
The Cosmological Bootstrap: Spinning correlators from symmetries and factorization (2020, background): “Such a classification would provide the conceptual foundation for the discipline of “cosmological collider physics” [13–39], and facilitate a deeper understanding of theoretical constraints on cosmological correlators.”
Prospects for cosmological collider physics (2016, methodology): “The possible amplitudes of these bispectra span a wide range of values, and strongly depend on the nature of couplings in the model [2, 3, 20, 29].”
The cosmological bootstrap: inflationary correlators from symmetries and singularities (2018, unknown): “s. To achieve larger levels of non-Gaussianity, fNL >1, requires interactions that break the conformal symmetry more strongly, as in models with a reduced sound speed of the in ationary uctuations [56,109{111], or strongly coupled uctuations, as in some holographic models of dS/CFT [112]. While t”
The cosmological bootstrap: weight-shifting operators and scalar seeds (2019, background): “) Although these solutions describe static boundary correlators, they encode time-dependent processes in the bulk, including the production and decay of very massive particles [12, 35–55].”
A Mellin space approach to cosmological correlators (2019, unknown): “[6–18] for some recent efforts.”
CMB-S4 Science Case, Reference Design, and Project Plan (2019, background): “In addition, theoretical consistency conditions between scalar and tensor non-Gaussianities provide a compelling observational target [28, 29, 30].”
The Simons Observatory: science goals and forecasts (2018, background): “Interestingly, tensor non-Gaussianities are hard to produce (Bordin et al. 2016) and a detection would almost certainly signal new physics, such as the presence of higher-order massive spin particles (Lee et al. 2016; Baumann et al. 2018), or extra gauge particles (Agrawal et al. 2018).”
Schwinger-Keldysh diagrammatics for primordial perturbations (2017, background): “More details on mode functions of bosonic higher spin fields during inflation can be found in [33].”