The Lyman-alpha Forest as a tool for disentangling non-Gaussianities

TL;DR

This paper explores how the Lyman-alpha forest can be used to distinguish different types of primordial non-Gaussianities, specifically f_NL and g_NL, through flux bias calculations and transformations.

Contribution

It provides explicit expressions for flux biases caused by f_NL and g_NL and introduces a flux transformation method to disentangle these effects effectively.

Findings

Flux bias expressions for f_NL and g_NL derived.

Flux transformation allows clear separation of non-Gaussian effects.

Method maintains error control in measurements.

Abstract

Detection of primordial non-Gaussianity will give us an unprecedented detail of the physics of inflation. As observational probes are now exploring new expanses of the inflationary landscape, it is crucial to distinguish and disentangle effects of various non-Gaussianities beyond f_NL. In this work, we calculate the effects of non-Gaussianities parametrized by f_NL and the cubic-order g_NL, on the Lyman-alpha-forest flux measurements. We give the expressions of the bias due to f_NL and g_NL, which can be deduced from accurate measurements of the transmitted flux. We show how these two effects can be cleanly disentangled via a flux transformation, which also keeps the error in check.