Heavy Particle Signatures in Cosmological Correlation Functions with Tensor Modes

Understand

We explore the possibility to make use of cosmological data to look for signatures of unknown heavy particles whose masses are on the order of the Hubble parameter during the time of inflation.

• To be more specific we take up the quasi-single field inflation model, in which the isocurvaton $\sigma $ is supposed to be the heavy particle.
• We study correlation functions involving both scalar ($\zeta $) and tensor ($\gamma $) perturbations and search for imprints of the $\sigma$-particle effects.
• We make use of the technique of the effective field theory for inflation to derive the $\zeta \sigma $ and $\gamma \zeta \sigma $ couplings.