New shapes of primordial non-Gaussianity from quasi-single field inflation with multiple isocurvatons

Journal Article · 22 August 2019 · Physical Review D

DOI: https://doi.org/10.1103/PhysRevD.100.043534 · OSTI ID:1599365

McAneny, Michael ^[1]; Ridgway, Alexander K. ^[1]

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1. California Inst. of Technology (CalTech), Pasadena, CA (United States). Walter Burke Inst. for Theoretical Physics

Here, we study a simple extension of quasi-single field inflation in which the inflaton interacts with multiple extra massive scalars known as isocurvatons. Due to the breaking of time translational invariance by the inflaton background, the theory includes kinetic mixings among the inflaton and isocurvatons. These mixings give rise to novel new features in the primordial non-Gaussianities of the scalar curvature perturbation. A noteworthy feature is that the amplitude of the squeezed bispectrum can grow nearly as $(k_s/k_l{)}^{-3}$ while oscillating as $\cos \gamma \log (k_s/k_l)$, where $k_s/k_l$ is the ratio of the lengths of the short and long wave vectors. Observation of such a shape would provide evidence for the existence of multiple isocurvatons during inflation. Furthermore, we consider the effects of these non-Gaussianities on large-scale structure.

• Research Organization: California Institute of Technology (CalTech), Pasadena, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Grant/Contract Number: SC0011632
• OSTI ID: 1599365
• Alternate ID(s): OSTI ID: 1558687
• Journal Information: Physical Review D, Vol. 100, Issue 4; ISSN 2470-0010
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English