Imprints of Massive Scalars on Primordial Non-Gaussianities

Author: Ridgway, Alexander Karas

Year: 2019

Degree: Dissertation (Ph.D.)

Advisor: Wise, Mark B.

Committee Members: Cheung, Clifford W.; Doré, Olivier P.; Kapustin, Anton N.; Wise, Mark B.

Option: Physics

DOI: 10.7907/0FD0-GY68

Abstract

In this thesis, we modify the standard single-field inflation scenario by adding additional massive scalars to the inflationary field content. Due to the breaking of time translational invariance by the inflaton background, the inflaton can interact with these extra scalars through a kinetic mixing term. If these scalars have self- interactions, then their kinetic mixings with the inflaton induce potentially large primordial non-gaussianities in the scalar curvature fluctuations, which could be observed in the cosmic microwave background (CMB) and large-scale structure (LSS). We derive expressions for these non-Gaussianities in the limits the scalar masses are much larger than or much smaller than the Hubble constant during inflation and compute their contributions to dark matter halo correlation functions.

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