Constraints on long-lived, higher-spin particles from galaxy bispectrum

TL;DR

This paper explores how upcoming galaxy surveys can constrain the presence of long-lived, higher-spin particles during inflation by analyzing their distinctive angular signatures in the galaxy bispectrum.

Contribution

It provides a forecast for constraining higher-spin particles' signatures in the galaxy bispectrum using upcoming survey data, focusing on long-lived particles with angular dependence.

Findings

Forecasted constraints on higher-spin particles from EUCLID survey

Identified the angular dependence as a key signature for detection

Showed potential to detect or rule out certain particle properties

Abstract

The presence of massive particles with spin during inflation induces distinct signatures on correlation functions of primordial curvature fluctuations. In particular, the bispectrum of primordial perturbations obtains an angular dependence determined by the spin of the particle, which can be used to set constraints on the presence of such particles. If these particles are long-lived on super-Hubble scales, as is the case for example for partially massless particles, their imprint on correlation functions of curvature perturbations would be unsuppressed. In this paper, we make a forecast for how well such angular dependence can be constrained by the upcoming EUCLID spectroscopic survey via the measurement of galaxy bispectrum.