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Register a new userThe Hubble Tension in Light of the Full-Shape Analysis of Large-Scale Structure Data
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The disagreement between direct late-time measurements of the Hubble constant from the SH0ES collaboration, and early-universe measurements based on the $Lambda$CDM model from the Planck collaboration might, at least in principle, be explained by new physics in the early universe. Recently, the application of the Effective Field Theory of Large-Scale Structure to the full shape of the power spectrum of the SDSS/BOSS data has revealed a new, rather powerful, way to measure the Hubble constant and the other cosmological parameters from Large-Scale Structure surveys. In light of this, we analyze two models for early universe physics, Early Dark Energy and Rock n Roll, that were designed to significantly ameliorate the Hubble tension. Upon including the information from the full shape to the Planck, BAO, and Supernovae measurements, we find that the degeneracies in the cosmological parameters that were introduced by these models are well broken by the data, so that these two models do not significantly ameliorate the tension.
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The Effective Field Theory of Large-Scale Structure (EFTofLSS) is a formalism that allows us to predict the clustering of Cosmological Large-Scale Structure in the mildly non-linear regime in an accurate and reliable way. After validating our technique against several sets of numerical simulations, we perform the analysis for the cosmological parameters of the DR12 BOSS data. We assume $Lambda$CDM, a fixed value of the baryon/dark-matter ratio, $Omega_b/Omega_c$, and of the tilt of the primordial power spectrum, $n_s$, and no significant input from numerical simulations. By using the one-loop power spectrum multipoles, we measure the primordial amplitude of the power spectrum, $A_s$, the abundance of matter, $Omega_m$, and the Hubble parameter, $H_0$, to about $13%$, $3.2%$ and $3.2%$ respectively, obtaining $ln(10^{10}As)=2.72pm 0.13$, $Omega_m=0.309pm 0.010$, $H_0=68.5pm 2.2$ km/(s Mpc) at 68% confidence level. If we then add a CMB prior on the sound horizon, the error bar on $H_0$ is reduced to $1.6%$. These results are a substantial qualitative and quantitative improvement with respect to former analyses, and suggest that the EFTofLSS is a powerful instrument to extract cosmological information from Large-Scale Structure.
The precision of the cosmological data allows us to accurately approximate the predictions for cosmological observables by Taylor expanding up to a low order the dependence on the cosmological parameters around a reference cosmology. By applying this observation to the redshift-space one-loop galaxy power spectrum of the Effective Field Theory of Large-Scale Structure, we analyze the BOSS DR12 data by scanning over all the parameters of $Lambda$CDM cosmology with massive neutrinos. We impose several sets of priors, the widest of which is just a Big Bang Nucleosynthesis prior on the current fractional energy density of baryons, $Omega_b h^2$, and a bound on the sum of neutrino masses to be less than 0.9 eV. In this case we measure the primordial amplitude of the power spectrum, $A_s$, the abundance of matter, $Omega_m$, the Hubble parameter, $H_0$, and the tilt of the primordial power spectrum, $n_s$, to about $19%$, $5.7%$, $2.2%$ and $7.3%$ respectively, obtaining $ln ( 10^{10} A_s) =2.91pm 0.19$, $Omega_m=0.314pm 0.018$, $H_0=68.7pm 1.5$ km/(s Mpc) and $n_s=0.979pm 0.071$ at $68%$ confidence level. A public code is released with this preprint.
We re-analyze the Cepheid data used to infer the value of $H_0$ by calibrating SnIa. We do not enforce a universal value of the empirical Cepheid calibration parameters $R_W$ (Cepheid Wesenheit color-luminosity parameter) and $M_H^{W}$ (Cepheid Wesenheit H-band absolute magnitude). Instead, we allow for variation of either of these parameters for each individual galaxy. We also consider the case where these parameters have two universal values: one for low galactic distances $D<D_c$ and one for high galactic distances $D>D_c$ where $D_c$ is a critical transition distance. We find hints for a $3sigma$ level mismatch between the low and high galactic distance parameter values. We then use AIC and BIC criteria to compare and rank the following types of models: Base models: Universal values for $R_W$ and $M_H^{W}$ (no parameter variation), I Individual fitted galactic $R_W$ with a universal fitted $M_H^{W}$, II Universal fixed $R_W$ with individual fitted galactic $M_H^{W}$, III Universal fitted $R_W$ with individual fitted galactic $M_H^{W}$, IV Two universal fitted $R_W$ (near and far) with one universal fitted $M_H^{W}$, V Universal fitted $R_W$ with two universal fitted $M_H^{W}$ (near and far), VI Two universal fitted $R_W$ with two universal fitted $M_H^{W}$ (near and far). We find that the AIC and BIC criteria consistently favor model IV instead of the commonly used Base model where no variation is allowed for the Cepheid empirical parameters. The best fit value of the SnIa absolute magnitude $M_B$ and of $H_0$ implied by the favored model IV is consistent with the inverse distance ladder calibration based on the CMB sound horizon $H_0=67.4pm 0.5,km,s^{-1},Mpc^{-1}$. Thus in the context of the favored model IV the Hubble crisis is not present. This model may imply the presence of a fundamental physics transition taking place at a time more recent than $100,Myrs$ ago.
Although cosmic microwave background (CMB) is the most powerful cosmological probe of neutrino masses, it is in trouble with local direct measurements of $H_0$, which is called the $H_0$ tension. Since neutrino masses are correlated with $H_0$ in CMB, one can expect the cosmological bound on neutrino masses would be much affected by the $H_0$ tension. We investigate what impact this tension brings to cosmological bound on neutrino masses by assuming a model with modified recombination which has been shown to resolve the tension. We argue that constraints on neutrino masses become significantly weaker in models where the $H_0$ tension can be resolved.
The $Lambda$CDM prediction of $S_8equivsigma_8(Omega_m/0.3)^{0.5}$ -- where $sigma_8$ is the root mean square of matter fluctuations on a 8 $h^{-1}$Mpc scale -- once calibrated on Planck CMB data is $2-3sigma$ lower than its direct estimate by a number of weak lensing surveys. In this paper, we explore the possibility that the $S_8$-tension is due to a non-thermal hot dark matter (HDM) fractional contribution to the universe energy density leading to a power suppression at small-scales in the matter power spectrum. Any HDM models can be characterized by its effective mass $ m_{sp}^{rm eff}$ and its contribution to the relativistic degrees of freedom at CMB decoupling $Delta N_{rm eff}$. Taking the specific example of a sterile particle produced from the decay of the inflaton during a matter dominated era, we find that from Planck only the tension can be reduced below $2sigma$, but Planck does not favor a non-zero ${m_{sp}^{rm eff},Delta N_{rm eff}}$. In combination with a measurement of $S_8$ from KIDS1000+BOSS+2dfLenS, the $S_8$-tension would hint at the existence of a particle of mass $ m_{sp}^{rm eff} simeq 0.67_{-0.48}^{+0.26}$ ${rm eV}$ with a contribution to $Delta N_{rm eff} simeq0.06pm0.05$. However, Pantheon and BOSS BAO/$fsigma_8$ data restricts the particle mass to $m_{sp}^{rm eff} simeq 0.48_{-0.36}^{+0.17}$ and contribution to $Delta N_{rm eff} simeq 0.046_{-0.031}^{+0.004}$. We discuss implications of our results for other canonical non-thermal HDM models -- the Dodelson-Widrow model and a thermal sterile particle with a different temperature in the hidden sector. We report competitive results on such hidden sector temperature which might have interesting implications for particle physics model building, in particular connecting the $S_8$-tension to the longstanding short baseline oscillation anomaly.
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