_version_ 1866913721287180288
author Whitford, Abbé M.
Rivera-Morales, Hugo
Howlett, Cullan
Vargas-Magaña, Mariana
Fromenteau, Sébastien
Davis, Tamara M.
Pérez-Fernández, Alejandro
de Mattia, Arnaud
Ahlen, Steven
Bianchi, Davide
Brooks, David
Burtin, Etienne
Claybaugh, Todd
de la Macorra, Axel
Doel, Peter
Ferraro, Simone
Forero-Romero, Jaime E.
Gaztañaga, Enrique
Gontcho, Satya Gontcho A
Gutierrez, Gaston
Juneau, Stephanie
Kehoe, Robert
Kirkby, David
Kisner, Theodore
Koposov, Sergey
Landriau, Martin
Guillou, Laurent Le
Meisner, Aaron
Miquel, Ramon
Prada, Francisco
Pérez-Ràfols, Ignasi
Rossi, Graziano
Sanchez, Eusebio
Schubnell, Michael
Sprayberry, David
Tarlé, Gregory
Weaver, Benjamin Alan
Zarrouk, Pauline
Zou, Hu
author_facet Whitford, Abbé M.
Rivera-Morales, Hugo
Howlett, Cullan
Vargas-Magaña, Mariana
Fromenteau, Sébastien
Davis, Tamara M.
Pérez-Fernández, Alejandro
de Mattia, Arnaud
Ahlen, Steven
Bianchi, Davide
Brooks, David
Burtin, Etienne
Claybaugh, Todd
de la Macorra, Axel
Doel, Peter
Ferraro, Simone
Forero-Romero, Jaime E.
Gaztañaga, Enrique
Gontcho, Satya Gontcho A
Gutierrez, Gaston
Juneau, Stephanie
Kehoe, Robert
Kirkby, David
Kisner, Theodore
Koposov, Sergey
Landriau, Martin
Guillou, Laurent Le
Meisner, Aaron
Miquel, Ramon
Prada, Francisco
Pérez-Ràfols, Ignasi
Rossi, Graziano
Sanchez, Eusebio
Schubnell, Michael
Sprayberry, David
Tarlé, Gregory
Weaver, Benjamin Alan
Zarrouk, Pauline
Zou, Hu
contents In the early Universe, neutrinos decouple quickly from the primordial plasma and propagate without further interactions. The impact of free-streaming neutrinos is to create a temporal shift in the gravitational potential that impacts the acoustic waves known as baryon acoustic oscillations (BAOs), resulting in a non-linear spatial shift in the Fourier-space BAO signal. In this work, we make use of and extend upon an existing methodology to measure the phase shift amplitude $β_ϕ$ and apply it to the DESI Data Release 1 (DR1) BAOs with an anisotropic BAO fitting pipeline. We validate the fitting methodology by testing the pipeline with two publicly available fitting codes applied to highly precise cubic box simulations and realistic simulations representative of the DESI DR1 data. We find further study towards the methods used in fitting the BAO signal will be necessary to ensure accurate constraints on $β_ϕ$ in future DESI data releases. Using DESI DR1, we present individual measurements of the anisotropic BAO distortion parameters and the $β_ϕ$ for the different tracers, and additionally a combined fit to $β_ϕ$ resulting in $β_ϕ = 2.7 \pm 1.7$. After including a prior on the distortion parameters from constraints using \textit{Planck} we find $β_ϕ = 2.7^{+0.60}_{-0.67} $ suggesting $β_ϕ > 0$ at 4.3$σ$ significance. This result may hint at a phase shift that is not purely sourced from the standard model expectation for $N_{\rm{eff}}$ or could be a upwards statistical fluctuation in the measured $β_ϕ$; this result relaxes in models with additional freedom beyond $Λ$CDM.
format Preprint
id arxiv_https___arxiv_org_abs_2412_05990
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Constraining the phase shift of relativistic species in DESI BAOs
Whitford, Abbé M.
Rivera-Morales, Hugo
Howlett, Cullan
Vargas-Magaña, Mariana
Fromenteau, Sébastien
Davis, Tamara M.
Pérez-Fernández, Alejandro
de Mattia, Arnaud
Ahlen, Steven
Bianchi, Davide
Brooks, David
Burtin, Etienne
Claybaugh, Todd
de la Macorra, Axel
Doel, Peter
Ferraro, Simone
Forero-Romero, Jaime E.
Gaztañaga, Enrique
Gontcho, Satya Gontcho A
Gutierrez, Gaston
Juneau, Stephanie
Kehoe, Robert
Kirkby, David
Kisner, Theodore
Koposov, Sergey
Landriau, Martin
Guillou, Laurent Le
Meisner, Aaron
Miquel, Ramon
Prada, Francisco
Pérez-Ràfols, Ignasi
Rossi, Graziano
Sanchez, Eusebio
Schubnell, Michael
Sprayberry, David
Tarlé, Gregory
Weaver, Benjamin Alan
Zarrouk, Pauline
Zou, Hu
Cosmology and Nongalactic Astrophysics
In the early Universe, neutrinos decouple quickly from the primordial plasma and propagate without further interactions. The impact of free-streaming neutrinos is to create a temporal shift in the gravitational potential that impacts the acoustic waves known as baryon acoustic oscillations (BAOs), resulting in a non-linear spatial shift in the Fourier-space BAO signal. In this work, we make use of and extend upon an existing methodology to measure the phase shift amplitude $β_ϕ$ and apply it to the DESI Data Release 1 (DR1) BAOs with an anisotropic BAO fitting pipeline. We validate the fitting methodology by testing the pipeline with two publicly available fitting codes applied to highly precise cubic box simulations and realistic simulations representative of the DESI DR1 data. We find further study towards the methods used in fitting the BAO signal will be necessary to ensure accurate constraints on $β_ϕ$ in future DESI data releases. Using DESI DR1, we present individual measurements of the anisotropic BAO distortion parameters and the $β_ϕ$ for the different tracers, and additionally a combined fit to $β_ϕ$ resulting in $β_ϕ = 2.7 \pm 1.7$. After including a prior on the distortion parameters from constraints using \textit{Planck} we find $β_ϕ = 2.7^{+0.60}_{-0.67} $ suggesting $β_ϕ > 0$ at 4.3$σ$ significance. This result may hint at a phase shift that is not purely sourced from the standard model expectation for $N_{\rm{eff}}$ or could be a upwards statistical fluctuation in the measured $β_ϕ$; this result relaxes in models with additional freedom beyond $Λ$CDM.
title Constraining the phase shift of relativistic species in DESI BAOs
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2412.05990