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Main Authors: Ebina, Haruki, White, Martin
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2401.13166
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author Ebina, Haruki
White, Martin
author_facet Ebina, Haruki
White, Martin
contents Near-future facilities observing the high-redshift universe ($2<z<5$) will have an opportunity to take advantage of "multi-tracer" cosmology by observing multiple tracers of the matter density field: Lyman alpha emitters (LAE), Lyman break galaxies (LBG), and CMB lensing $κ$. In this work we use Fisher forecasts to investigate the effect of multi-tracers on next-generation facilities. In agreement with previous work, we show that multiple tracers improve constraints primarily from degeneracy breaking, instead of the traditional intuition of sample variance cancellation. Then, we forecast that for both BBN and CMB primary priors, the addition of lensing and LAEs onto a LBG-only sample will gain 25\% or more in many parameters, with the largest gains being factor of $\sim10$ improvement for $f_{\rm EDE}$. We include a preliminary approach towards modelling the impact of radiative transfer (RT) on forecasts involving LAEs by introducing a simplified model at linear theory level. Our results, albeit preliminary, show that the while RT influences LAE-only forecasts strongly, its effect on composite multi-tracer forecasts are limited.
format Preprint
id arxiv_https___arxiv_org_abs_2401_13166
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Cosmology before noon with multiple galaxy populations
Ebina, Haruki
White, Martin
Cosmology and Nongalactic Astrophysics
Near-future facilities observing the high-redshift universe ($2<z<5$) will have an opportunity to take advantage of "multi-tracer" cosmology by observing multiple tracers of the matter density field: Lyman alpha emitters (LAE), Lyman break galaxies (LBG), and CMB lensing $κ$. In this work we use Fisher forecasts to investigate the effect of multi-tracers on next-generation facilities. In agreement with previous work, we show that multiple tracers improve constraints primarily from degeneracy breaking, instead of the traditional intuition of sample variance cancellation. Then, we forecast that for both BBN and CMB primary priors, the addition of lensing and LAEs onto a LBG-only sample will gain 25\% or more in many parameters, with the largest gains being factor of $\sim10$ improvement for $f_{\rm EDE}$. We include a preliminary approach towards modelling the impact of radiative transfer (RT) on forecasts involving LAEs by introducing a simplified model at linear theory level. Our results, albeit preliminary, show that the while RT influences LAE-only forecasts strongly, its effect on composite multi-tracer forecasts are limited.
title Cosmology before noon with multiple galaxy populations
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2401.13166