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Main Authors: Gaines, Sasha, Nikakhtar, Farnik, Padmanabhan, Nikhil, Sheth, Ravi K.
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2408.00072
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author Gaines, Sasha
Nikakhtar, Farnik
Padmanabhan, Nikhil
Sheth, Ravi K.
author_facet Gaines, Sasha
Nikakhtar, Farnik
Padmanabhan, Nikhil
Sheth, Ravi K.
contents The location of the baryon acoustic oscillation (BAO) feature in the two-point correlation function (2PCF) of matter produces a standard ruler that is useful for the measurement of the expansion history of the Universe. Inspired by the possibility of reconstructing the positions of protohalos in the initial density field with a novel method rooted in optimal transport theory, we revisit the BAO signal in the protohalo correlation function. Our work examines the performance of a template 2PCF built on a tracer bias relation that includes scale dependence -- a term that can be motivated by peaks theory or a general bias expansion. Working in protohalos, halos, and the linear combination of the protohalo and matter fields that is motivated by the continuity equation, we demonstrate that this model accurately captures the shape of the BAO feature and improves the precision of the BAO scale measurement relative to a model that does not include scale-dependent bias by 47% in protohalos, 15% in halos, and 14% in the linear combination of the protohalo and matter fields. Allowing for scale dependence does not appear to introduce any shift in the BAO feature. The precision of the BAO distance scale estimate is highest with the linear combination of the protohalo and matter fields, which offers a factor of 3.5 improvement over Eulerian-space measurements and a factor of 4-8 improvement over the estimate made with protohalos alone.
format Preprint
id arxiv_https___arxiv_org_abs_2408_00072
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Leveraging protohalos and scale-dependent bias to calibrate the BAO scale in real space
Gaines, Sasha
Nikakhtar, Farnik
Padmanabhan, Nikhil
Sheth, Ravi K.
Cosmology and Nongalactic Astrophysics
The location of the baryon acoustic oscillation (BAO) feature in the two-point correlation function (2PCF) of matter produces a standard ruler that is useful for the measurement of the expansion history of the Universe. Inspired by the possibility of reconstructing the positions of protohalos in the initial density field with a novel method rooted in optimal transport theory, we revisit the BAO signal in the protohalo correlation function. Our work examines the performance of a template 2PCF built on a tracer bias relation that includes scale dependence -- a term that can be motivated by peaks theory or a general bias expansion. Working in protohalos, halos, and the linear combination of the protohalo and matter fields that is motivated by the continuity equation, we demonstrate that this model accurately captures the shape of the BAO feature and improves the precision of the BAO scale measurement relative to a model that does not include scale-dependent bias by 47% in protohalos, 15% in halos, and 14% in the linear combination of the protohalo and matter fields. Allowing for scale dependence does not appear to introduce any shift in the BAO feature. The precision of the BAO distance scale estimate is highest with the linear combination of the protohalo and matter fields, which offers a factor of 3.5 improvement over Eulerian-space measurements and a factor of 4-8 improvement over the estimate made with protohalos alone.
title Leveraging protohalos and scale-dependent bias to calibrate the BAO scale in real space
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2408.00072