Linear Point Standard Ruler: cosmological forecasts for future galaxy surveys. Toward consistent BAO analyses far from a fiducial cosmology

Anselmi, Stefano; Starkman, Glenn D.; Renzi, A.

doi:10.48550/arxiv.2205.09098

Cited by 4 publications

(2 citation statements)

References 45 publications

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“…BAO scale measurements may be biased or their uncertainties might be underestimated for this class of non-ΛCDM cosmology [66,67], something that requires further calibration in mock observations. Nevertheless, this effectively negative early dark energy component, realised through the CGG, deserves more study.…”

Section: Jcap03(2024)045mentioning

confidence: 99%

A cosmic glitch in gravity

Wen,

Hergt,

Afshordi

et al. 2024

J. Cosmol. Astropart. Phys.

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We investigate a model that modifies general relativity on cosmological scales, specifically by having a `glitch' in the gravitational constant between the cosmological (super-horizon) and Newtonian (sub-horizon) regimes, as motivated e.g. in the Hořava-Lifshitz proposal or in the Einstein-aether framework. This gives a single-parameter extension to the standard ΛCDM model, which is equivalent to adding a dark energy component, but where the energy density of this component can have either sign. Fitting to data from the Planck satellite, we find that negative contributions are, in fact, preferred. Additionally, we find that roughly one percent weaker superhorizon gravity can somewhat ease the Hubble and clustering tensions in a range of cosmological observations, although at the expense of spoiling fits to the baryonic acoustic oscillation scale in galaxy surveys. Therefore, the extra parametric freedom offered by our model deserves further exploration, and we discuss how future observations may elucidate this potential cosmic glitch in gravity, through a four-fold reduction in statistical uncertainties.

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Section: Jcap03(2024)045mentioning

confidence: 99%

A cosmic glitch in gravity

Wen,

Hergt,

Afshordi

et al. 2024

J. Cosmol. Astropart. Phys.

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“…Therefore, LP is promising for exploring cosmological models beyond LCDM. The forecast of 𝑠 LP /𝐷 V (Anselmi et al 2022), assuming DESI 1 (DESI Collaboration et al 2016) and Euclid 2 (Laureĳs et al 2011), has a little larger uncertainty than standard templatebased BAO measured 𝑟 d /𝐷 V , but more accurate than results from Purely-Geometric-BAO (PG-BAO) method, which is a correlationfunction model-fitting (CF-MF) analysis relies on a phenomenological cosmological model for the correlation function.…”

Section: Introductionmentioning

confidence: 99%

Cosmological constraints with the linear point from the BOSS survey

He¹,

Zhao²,

Shan³

2023

Preprint

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The Linear Point (LP), defined as the midpoint between the BAO peak and the associated left dip of the two-point correlation function (2PCF), 𝜉 (𝑠), is proposed as a new standard ruler which is insensitive to nonlinear effects. In this paper, we use a Bayesian sampler to measure the LP and estimate the corresponding statistical uncertainty, and then perform cosmological parameter constraints with LP measurements. Using the Patchy mock catalogues, we find that the measured LPs are consistent with theoretical predictions at 0.6 per cent level. We find constraints with midpoints identified from the rescaled 2PCF (𝑠 2 𝜉) more robust than those from the traditional LP based on 𝜉, as the BAO peak is not always prominent when scanning the cosmological parameter space, with the cost of 2-4 per cent increase of statistical uncertainty. This problem can also be solved by an additional dataset that provides strong parameter constraints. Measuring LP from the reconstructed data slightly increases the systematic error but significantly reduces the statistical error, resulting in more accurate measurements. The 1 𝜎 confidence interval of distance scale constraints from LP measurements are 20-30 per cent larger than those of the corresponding BAO measurements. For the reconstructed SDSS DR12 data, the constraints on 𝐻 0 and Ω m in a flat-ΛCDM framework with the LP are generally consistent with those from BAO. When combined with Planck cosmic microwave background data, we obtain 𝐻 0 = 68.02 +0.36 −0.37 km s −1 Mpc −1 and Ω m = 0.3055 +0.0049 −0.0048 with the LP.

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Cosmological constraints with the linear point from the BOSS survey

Zhao

Shan

2023

Monthly Notices of the Royal Astronomical Society

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The Linear Point (LP), defined as the midpoint between the BAO peak and the associated left dip of the two-point correlation function (2PCF), ξ(s), is proposed as a new standard ruler which is insensitive to nonlinear effects. In this paper, we use a Bayesian sampler to measure the LP and estimate the corresponding statistical uncertainty, and then perform cosmological parameter constraints with LP measurements. Using the Patchy mock catalogues, we find that the measured LPs are consistent with theoretical predictions at 0.6 per cent level. We find constraints with midpoints identified from the rescaled 2PCF (s2ξ) more robust than those from the traditional LP based on ξ, as the BAO peak is not always prominent when scanning the cosmological parameter space, with the cost of 2–4 per cent increase of statistical uncertainty. This problem can also be solved by an additional dataset that provides strong parameter constraints. Measuring LP from the reconstructed data slightly increases the systematic error but significantly reduces the statistical error, resulting in more accurate measurements. The 1 σ confidence interval of distance scale constraints from LP measurements are 20–30 per cent larger than those of the corresponding BAO measurements. For the reconstructed SDSS DR12 data, the constraints on H0 and Ωm in a flat-ΛCDM framework with the LP are generally consistent with those from BAO. When combined with Planck cosmic microwave background data, we obtain $H_0=68.02_{-0.37}^{+0.36}$ km s−1 Mpc−1 and $\Omega _{\rm m}=0.3055_{-0.0048}^{+0.0049}$ with the LP.

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Linear Point Standard Ruler: cosmological forecasts for future galaxy surveys. Toward consistent BAO analyses far from a fiducial cosmology

Cited by 4 publications

References 45 publications

A cosmic glitch in gravity

A cosmic glitch in gravity

Cosmological constraints with the linear point from the BOSS survey

Cosmological constraints with the linear point from the BOSS survey

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