Unraveling the effective fluid approach for 
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 models in the subhorizon approximation

The EG statistic is a powerful probe for detecting deviations from GR by combining weak lensing (WL), real-space clustering and redshift space distortion (RSD) measurements thus probing both the lensing and the growth effective Newton constants (GL and G ef f ). We construct an up to date compilation of EG statistic data including both redshift and scale dependence (EG(R, z)). We combine this EG data compilation with an up to date compilation of f σ8 data from RSD observations to identify the current level of tension between the Planck/ΛCDM standard model based on general relativity and a general model independent redshift evolution parametrization of GL and G ef f . Each f σ8 datapoint considered has been published separately in the context of independent analyses of distinct galaxy samples. However, there are correlations among the datapoints considered due to overlap of the analyzed galaxy samples. Due to these correlations the derived levels of tension of the best fit parameters with Planck/ΛCDM are somewhat overestimated but this is the price to pay for maximizing the information encoded in the compilation considered. We find that the level of tension increases from about 3.5σ for the f σ8 data compilation alone to about 6σ when the EG data are also included in the analysis. The direction of the tension is the same as implied by the f σ8 RSD growth data alone (lower Ωm and/or weaker effective Newton constant at low redshifts for both the lensing and the growth effective Newton constants (GL and G ef f )). These results further amplify the hints for weakening modified gravity discussed in other recent analyses [1][2][3][4].

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“…where primes denote differentiation with respect to the redshift. While in terms of the scale factor we have [52,101,111]…”

Section: Ii2 the Effective Newton's Constant Parameter µ And The LImentioning

confidence: 99%

Tension of the EG statistic and redshift space distortion data with the Planck - ΛCDM model and implications for weakening gravity

Skara

Perivolaropoulos

2020

Phys. Rev. D

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“…The methodology used to handle the data relies on the Markov Chain Monte Carlo (MCMC) technique based on the Metropolis-Hasting algorithm with a modified version of the original available publicly Mathematica TM code from refs. [37,38]. We apply our χ 2 -statistics to the joint likelihood of the 1107 data points.…”

Section: Cosmological Datamentioning

confidence: 99%

“…We perform the Markov Chain Monte Carlo (MCMC) sample technique with a modified version of the available publicly code [37,38] written in Mathematica TM software using the joint likelihood of kinematical probes as of the Cosmic Microwave Background (CMB) Planck 2018 [1] datasets of TT,TE,EE+lowE on 68% interval of the related cosmolog-0123456789(). : V,-vol ical parameters, the largest dataset Pantheon SnIa [39] with redshift ranging from 0.01 < z < 2.3, the Hubble parameter a function of redshift H (z) [40] and Baryonic Acoustic Oscillations (BAO) from points of the joint surveys 6dFGS [41], BOSS DR12 [42], SDSS DR7 MGS [43], eBOSS DR14 [44], BOSS DR12 Lyα forest [45] and BOSS DR11 Lyα forest [46].…”

Section: Introductionmentioning

confidence: 99%

Constraints on $$\sigma _8$$ and degeneracies from linear Nash-Greene perturbations in subhorizon scale

Capistrano

2020

Eur. Phys. J. C

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Using a joint statistical analysis, we test a four-dimensional FLRW model embedded in a five-dimensional bulk based on the Nash-Greene embedding theorem. Performing a Markov Chain Monte Carlo (MCMC) modelling, we combine observational data sets as those of the recent growth data, the best-fit Planck2018/$$\varLambda $$ Λ CDM parameters on the Cosmic Microwave Background (CMB), the Baryon Acoustic Oscillations (BAO) measurements, the Pantheon Supernovae type Ia and the Hubble parameter data. From linear Nash-Greene fluctuations of the metric, we show the related perturbed equations in longitudinal Newtonian gauge to obtain the evolution of growth matter. A mild alleviation may be obtained from the degeneracies on the model parameter analyzing the $$\sigma $$ σ tension between the growth amplitude factor and the matter content in the plane $$(\sigma _8$$ ( σ 8 -$$\varOmega _m)$$ Ω m ) on the observations from CMB and Large Scale Structure (LSS) probes. The Akaike Information Criterion (AIC) is also applied and we find a relative statistical consistence of the present model with both $$\varLambda $$ Λ CDM and wCDM models lower than 1$$\%$$ % of percentage difference at early times on the evolution of the Hubble function H(z). We also apply the Om(z) diagnosis to distinguish the present model from $$\varLambda $$ Λ CDM and wCDM models.

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“…in Refs. [7,[44][45][46][47][48][49][50][51]. 1 In certain cases we consider the deviation around Ωm =0.3 instead of Ωm =Ω P m (2) The observable f σ 8 (z) has a blind spot with respect to the parameter g a at redshift z 2.7.…”

Section: Growth Of Density Perturbationsmentioning

confidence: 99%

Constraining power of cosmological observables: Blind redshift spots and optimal ranges

2019

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2 − 3σ) is the Ω m − σ 8 tension between the CMB Planck data and the growth of density perturbations data (RSD and WL) [5][6][7][8][9]. The CMB data favor higher values of the matter density parameter Ω m and the matter fluctuations amplitude σ 8 than the data that probe directly the gravitational interaction (RSD and WL).A key question therefore arises: Are these tensions an early hint of new physics beyond the standard model or are they a result of systematic/statistical fluctuations in the data?Completed, ongoing and future CMB experiments and large scale structure surveys aim at testing the standard ΛCDM model and addressing the above question. These surveys are classified in four stages. Stages I and II correspond to completed surveys and CMB experiments, while stages III and IV correspond to ongoing and future projects respectively. For example stage II CMB experiments include WMAP [10], Planck [2, 3], ACTPol [11] and SPT-Pol [12], while stage III CMB experiments include AdvACT [13] and SPT-3G [14]. Future stage IV CMB probes on the ground[15] and in space such as Lite-BIRD [16, 17] mainly aim to measure CMB lensing and the CMB-B modes in detail.A large amount of high-quality data is expected in the coming years from large scale structure surveys (see Table I). Stage III large scale structure surveys include the Canada-France-Hawaii Telescope Lensing Survey [18], the Kilo Degree Survey (KiDS) [8,9], the extended arXiv:1812.05356v2 [astro-ph.CO]

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Unraveling the effective fluid approach for f(R) models in the subhorizon approximation

Cited by 96 publications

References 193 publications

Tension of the EG statistic and redshift space distortion data with the Planck - ΛCDM model and implications for weakening gravity

Tension of the EG statistic and redshift space distortion data with the Planck - ΛCDM model and implications for weakening gravity

Constraints on $$\sigma _8$$ and degeneracies from linear Nash-Greene perturbations in subhorizon scale

Constraining power of cosmological observables: Blind redshift spots and optimal ranges

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