Constraining Dark Acoustic Oscillations with the High-Redshift UV Luminosity Function

TL;DR

This paper uses high-redshift galaxy UV luminosity data to place constraints on dark acoustic oscillations in the matter power spectrum, providing model-agnostic bounds on their scale and amplitude.

Contribution

It introduces a phenomenological transfer function for DAOs, calibrates an Extended Press-Schechter model with simulations, and derives observational constraints from multiple telescopes.

Findings

DAO peak wave number constrained to be greater than 50 h/Mpc

Dark matter fraction with DAOs less than 7% is consistent with data

Provides bounds on small-scale features in the dark sector

Abstract

Dark acoustic oscillations (DAOs) in the matter power spectrum can arise in many different dark sector models, and can imprint on a variety of cosmological observables. In this work we use measurements of the galactic UV luminosity function (UVLF) at high redshifts to constrain the dark acoustic oscillation feature at small scales in a model-agnostic way. We introduce a phenomenological transfer function model for a dark sector with a species undergoing DAOs which can accommodate sub-dominant dark matter abundances, and obtain constraints on its parameters. In order to predict the UVLF, we employ an Extended Press-Schechter formalism which we calibrate using N-body simulations with initial conditions featuring DAOs. Using measurements from the Hubble Space Telescope, James Webb Space Telescope, Subaru Telescope, and Canada-France-Hawaii Telescope, we constrain the wave number of the first DAO peak to be at $k \gtrsim 50\ h/\mathrm{Mpc}$, unless the fraction of dark matter undergoing DAOs is less than $0.07$.