Hubble Constant H0 Research Articles

Analysing the large-scale bulk flow using cosmicflows4: increasing tension with the standard cosmological model

ABSTRACT We present an estimate of the bulk flow in a volume of radii 150−200 h−1 Mpc using the minimum variance method with data from the CosmicFlows-4 (CF4) catalogue. The addition of new data in the CF4 has resulted in an increase in the estimate of the bulk flow in a sphere of radius 150 h−1 Mpc relative to the CosmicFlows-3 (CF3). This bulk flow has an $\sim 0.015~{{\ \rm per\ cent}}$ chance of occurring in the standard cosmological model with cosmic microwave background derived parameters. Given that the CF4 is deeper than the CF3, we were able to use the CF4 to accurately estimate the bulk flow on scales of 200 h−1 Mpc (equivalent to 266 Mpc for Hubble constant H0 = 75 km s−1 Mpc−1) for the first time. This bulk flow is in even greater tension with the standard model, having $\sim 1.5\times 10^{-4}\ \%$ probability of occurring. To estimate the bulk flow accurately, we introduce a novel method to calculate distances and velocities from distance moduli that is unbiased and accurate at all distances. Our results are completely independent of the value of H0.

H0 tension in torsion-based modified gravity

The rising concern in the Hubble constant tension (H0 tension) of the cosmological models motivates the scientific community to search for alternative cosmological scenarios that could resolve the H0 tension. In this regard, we aim to work on a torsion-based modified theory of gravity which is an alternative description to the coherence model. We solve numerically for the Hubble parameter using two exponential Lagrangian functions of torsion T and a trace of energy-momentum tensor T for the dust case. Further, we constrain the cosmological and model parameters; to do that, we use Hubble, SNe Ia, Baryon Acoustic Oscillations, Cosmic Microwave Background samples, and Markov Chain Monte Carlo (MCMC) simulation through Bayesian statistics. We obtain the values of Hubble constant H0 for our model, and the outputs align with the recent observational measurements of H0. In addition, we check the deviation of our results from model-independent measurements of H0 from Planck2018, SH0ES, and H0LiCOW experiments. In contrast, our finding partially solved the H0 tension but gave a new possible direction to alleviate the H0 tension.

Fab-Four Cosmography to Tackle the Hubble Tension

In the context of the Fab-Four theory of gravity in a Friedmann-Lemaître-Robertson-Walker background, in this work we use the cosmography approach to study a particular self-tuning filter solution focused on a zero-curvature fixed point to study the H0 tension. In this scheme, the equations restrict the universe’s evolution to certain scenarios, including radiation-like expansion, matter-like expansion, and late-time acceleration. Furthermore, we build the cosmographic series of the Fab-Four theory to obtain the kinematic parameters as the Hubble constant H0 and the deceleration parameter q0 for all the scenarios mentioned. Finally, we compare our results to find that it is possible to alleviate the current discrepancy on H0 by considering specific requirements on the free parameters of the Fab-Four theory through a self-tuning filter.

Early dark energy with power-law F(R) gravity

We study a power-law F(R) gravity with an early dark energy term, that can describe both the early-time and the late-time acceleration of the Universe. We confront this scenario with recent observational data including the Pantheon Type Ia supernovae, measurements of the Hubble parameter H(z) (Cosmic Chronometers), data from Baryon Acoustic Oscillations and standard rulers data from the Cosmic Microwave Background (CMB) radiation. The model demonstrates some achievements in confronting with these observations and can be compared with the Λ-Cold-Dark-Matter model. In particular, in both models we obtain very close estimates for the Hubble constant H0, but it is not true for Ωm0. The early dark energy term supports viability of the considered F(R) gravity model.

Gravity in the local Universe: Density and velocity fields using CosmicFlows-4

This article publicly releases 3D reconstructions of the local Universe gravitational field below z = 0.8 that were computed using the CosmicFlows-4 (CF4) catalog of 56 000 galaxy distances and its subsample of 1008 supernovae distances. The article also provides measurements of the growth rate of structure using the pairwise correlation of radial peculiar velocities fσ8 = 0.38(±0.04) (ungrouped CF4), fσ8 = 0.36(±0.05) (grouped CF4), fσ8 = 0.30(±0.06) (supernovae), and of the bulk flow in the 3D-reconstructed local Universe 230 ± 136 km s1 at 300 h100−1 Mpc of distance from thes observer. The exploration of 10 000 reconstructions has led to the conclusion that the distances delivered by the CF4 catalog are compatible with a Hubble constant of H0 = 74.5 ± 0.1 (grouped CF4), H0 = 75.0 ± 0.35 (ungrouped CF4), and H0 = 75.5 ± 0.95 (CF4 supernovae subsample).

A new test of dynamical dark energy models and cosmic tensions in Hořava gravity

ABSTRACT Hořava gravity has been proposed as a renormalizable, higher derivative, Lorentz-violating quantum gravity model without ghost problems. A Hořava gravity-based dark energy (HDE) model for dynamical dark energy has also been proposed earlier by identifying all the extra (gravitational) contributions from the Lorentz-violating terms as an effective energy–momentum tensor in Einstein equation. We consider a complete cosmic microwave background, baryon acoustic oscillation (BAO), and supernova Ia data test of the HDE model by considering general perturbations over the background perfect HDE fluid. Except from BAO, we obtain the preference of non-flat universes for all other data set combinations. We obtain a positive result on the cosmic tensions between the Hubble constant H0 and the cosmic shear S8, because we have a shift of H0 towards a higher value, though not enough for resolving the H0 tension, but the value of S8 is unaltered. This is in contrast to a rather decreasing H0 but increasing S8 in a non-flat Lambda cold dark matter (LCDM). For all other parameters, like Ωm and $\Omega _\Lambda$, we obtain quite comparable results with those of LCDM for all data sets, especially with BAO, so that our results are close to a cosmic concordance between the data sets, contrary to the standard non-flat LCDM. We also obtain some undesirable features, like an almost null result on Ωk, which gives back the flat LCDM, if we do not predetermine the sign of Ωk, but we propose several promising ways for improvements by generalizing our analysis.

The Origin of Cosmic Structures Part 5— Resolution of the Hubble Tension Problem

The two principal contributors to the Hubble tension problem are the predictions of the baryonic acoustic oscillation model and the H0 parameter fit of the “Tip of the Red Giant Branch” collaboration. In this paper, we show that the former is neither necessary nor possible and that the latter yields a value in agreement with the supernovae results when adjustments are made for errors in the peculiar velocity model used to isolate the recession velocities of galaxies. We also make comparisons between the predictions of our new model of cosmology and the curve fits of the standard model. For values of redshift ≤ 1 we find that, with a Hubble constant of H0 = 73, the two agree almost exactly. We resolve the Hubble constant problem and validate the new model predictions for small redshifts.

H0 Tension on the Light of Supermassive Black Hole Shadows Data

Cosmological tensions in current times have opened a wide door to study new probes to constrain cosmological parameters, specifically, to determine the value of the Hubble constant H0 through independent techniques. The two standard methods to measure/infer H0 rely on: (i) anchored observables for the distance ladder, and (ii) establishing the relationship of the H0 to the angular size of the sound horizon in the recombination era assuming a standard Cosmological Constant Cold Dark Matter (ΛCDM) cosmology. However, the former requires a calibration with observables at nearby distances, while the latter is not a direct measurement and is model-dependent. The physics behind these aspects restrains our possibilities in selecting a calibration method that can help minimise the systematic effects or in considering a fixed cosmological model background. Anticipating the possibility of deeply exploring the physics of new nearby observables such as the recently detected black hole shadows, in this paper we propose standard rules to extend the studies related to these observables. Supermassive black hole shadows can be characterised by two parameters: the angular size of the shadow and the black hole mass. We found that it is possible to break the degeneracy between these parameters by forecasting and fixing certain conditions at high(er) redshifts, i.e., instead of considering the ≈10% precision from the EHT array, our results reach a ≈4%, a precision that could be achievable in experiments in the near future. Furthermore, we found that our estimations provide a value of H0=72.89±0.12 km/s/Mpc and, for the baryonic mass density, Ωm=0.275±0.002, showing an improvement in the values reported so far in the literature. We anticipate that our results can be a starting point for more serious treatments of the physics behind the SMBH shadow data as cosmological probes to relax tension issues.

On Low Hubble Expansion Rate from Planck Data Anomalies

From the linear perturbations of Nash–Greene fluctuations of a background metric, we obtain profiles of Hubble function evolution H(z) and fσ8(z) measurements as compared with the ΛCDM results at intermediate redshifts 0.1<z<1. For parameter estimation, we use joint data from Planck Cosmic Microwave Background (CMB) likelihoods of CMB temperature and polarization angular power spectra, Barionic Acoustic Oscillations (BAO) and local measurements of Hubble constant H0 from the Hubble Space Telescope (HST). We analyze the stability of the effective Newtonian constant Geff and its agreement with Big Bang Nucleosynthesis (BBN) constraints. We show that our results are highly compatible with the ΛCDM paradigm, rather extending the perspective for further studies on redshift-space galaxy clustering data. Moreover, we obtain the CMB TT angular spectra with the Integrated Sachs–Wolfe (ISW) effect, which is weakened on low-l scales. The resulting linear matter power spectrum P(k) profile is also compatible with ΛCDM results but somewhat degenerate with an early dark energy (DE) contribution. Finally, posing a dilemma to the solution of Hubble tension, our results indicate a low Hubble expansion rate suggesting possible anomalies in Planck data in consonance with the recent South Pole Telescope (SPT-3G) data.

Revising the Hubble constant, spatial curvature and dark energy dynamics with the latest observations of quasars

In this paper we use a newly compiled sample of ultra-compact structure in radio quasars and strong gravitational lensing systems with quasars acting as background sources to constrain six spatially flat and non-flat cosmological models (ΛCDM, PEDE, and DGP). These two sets of quasar data (time-delay measurements of six strong lensing systems and 120 intermediate-luminosity quasars calibrated as standard rulers) could break the degeneracy between the cosmological parameters (H0, Ωm, and Ωk), and therefore provide more stringent cosmological constraints for the six cosmological models we study. A joint analysis of the quasar sample provides model-independent measurements of the Hubble constant H0, which are strongly consistent with that derived from the local distance ladder by the SH0ES collaboration in the ΛCDM and PEDE model. However, in the framework of the DGP cosmology (especially for a flat universe), the measured Hubble constant is in good agreement with that derived from the recent Planck 2018 results. In addition, our results show that zero spatial curvature is supported by the current lensed and unlensed quasar observations and that there is no significant deviation from a flat universe. For most of the cosmological models we study (flat ΛCDM, non-flat ΛCDM, flat PEDE, and non-flat PEDE), the derived matter density parameter is completely consistent with Ωm ∼ 0.30 in all the data sets, as expected based on the latest cosmological observations. Finally, according to the statistical deviance information criterion (DIC), the joint constraints provide substantial observational support to the flat PEDE model; however, they do not rule out dark energy being a cosmological constant and non-flat spatial hypersurfaces.

The Hubble constant from two sibling Type Ia supernovae in the nearby galaxy NGC 4414: SN 1974G and SN 2021J

Having two “sibling” Type Ia supernovae (SNe Ia) in the same galaxy offers additional advantages in reducing a variety of systematic errors involved in estimating the Hubble constant, H0. NGC 4414 is a nearby galaxy included in the Hubble Space Telescope Key Project to measure its distance using Cepheid variables. It hosts two sibling SNe Ia: SN 2021J and SN 1974G. This provides the opportunity to improve the precision of the previous estimate of H0, which was based solely on SN 1974G. Here we present new optical BVRI photometry obtained at the Observatorio de Sierra Nevada and complement it with Swift UVOT UBV data, which cover the first 70 days of emission of SN 2021J. A first look at SN 2021J optical spectra obtained with the Gran Telescopio Canarias (GTC) reveals typical SN type Ia features. The main SN luminosity parameters for the two sibling SNe are obtained by using SNooPy, a light curve fitting code based on templates. Using a hierarchical bayesian approach, we build the Hubble diagram with a sample of 96 SNe Ia obtained from the Combined Pantheon Sample in the redshift range z = 0.02 − 0.075, and calibrate the zero point with the two sibling type-Ia SNe in NGC 4414. We report a value of the Hubble constant H0 = 72.19 ± 2.32 (stat.) ±3.42 (syst.) km s−1 Mpc−1. We expect a reduction of the systematic error after a new analysis of the Cepheids period-luminosity relation using the upcoming Gaia DR4 and additional Cepheids from the HST and JWST.

Revealing the late-time transition of H0: relieve the Hubble crisis

Abstract The discrepancy between the value of the Hubble constant H0 measured from the local distance ladder and from the cosmic microwave background is the most serious challenge to the standard ΛCDM model. Various models have been proposed to solve or relieve it, but no satisfactory solution has been given until now. Here, we report a late-time transition of H0, i.e. H0 changes from a low value to a high one from early to late cosmic time, by investigating the Hubble parameter H($\mathit{ z}$) data based on the Gaussian process (GP) method. This finding effectively reduces the Hubble crisis by 70 per cent. Our results are also consistent with the descending trend of H0 measured using time-delay cosmography of lensed quasars at 1 σ confidence level, and support the idea that the Hubble crisis arises from new physics beyond the standard ΛCDM model. In addition, in the ΛCDM model and $w$CDM model, there is no transition behaviour of H0.

A measurement of Hubble’s Constant using Fast Radio Bursts

ABSTRACT We constrain the Hubble constant H0 using Fast Radio Burst (FRB) observations from the Australian Square Kilometre Array Pathfinder (ASKAP) and Murriyang (Parkes) radio telescopes. We use the redshift-dispersion measure (‘Macquart’) relationship, accounting for the intrinsic luminosity function, cosmological gas distribution, population evolution, host galaxy contributions to the dispersion measure (DMhost), and observational biases due to burst duration and telescope beamshape. Using an updated sample of 16 ASKAP FRBs detected by the Commensal Real-time ASKAP Fast Transients (CRAFT) Survey and localized to their host galaxies, and 60 unlocalized FRBs from Parkes and ASKAP, our best-fitting value of H0 is calculated to be $73_{-8}^{+12}$ km s−1 Mpc−1. Uncertainties in FRB energetics and DMhost produce larger uncertainties in the inferred value of H0 compared to previous FRB-based estimates. Using a prior on H0 covering the 67–74 km s−1 Mpc−1 range, we estimate a median ${\rm DM}_{\rm host}= 186_{-48}^{+59}\,{\rm pc \, cm^{-3}}$, exceeding previous estimates. We confirm that the FRB population evolves with redshift similarly to the star-formation rate. We use a Schechter luminosity function to constrain the maximum FRB energy to be log10Emax$=41.26_{-0.22}^{+0.27}$ erg assuming a characteristic FRB emission bandwidth of 1 GHz at 1.3 GHz, and the cumulative luminosity index to be $\gamma =-0.95_{-0.15}^{+0.18}$. We demonstrate with a sample of 100 mock FRBs that H0 can be measured with an uncertainty of ±2.5 km s−1 Mpc−1, demonstrating the potential for clarifying the Hubble tension with an upgraded ASKAP FRB search system. Last, we explore a range of sample and selection biases that affect FRB analyses.

Corrected holographic dark energy with power-law entropy and Hubble Horizon cut-off in FRW Universe

In the present work, we investigate the power-law entropy corrected holographic dark energy (PLECHDE) model with Hubble horizon cutoff. We use 46 observational Hubble data points in the redshift range 0≤z≤2.36 to determine the present Hubble constant H0 and the model parameter n. It represents a phase transition of the universe from deceleration to acceleration and has the transition point at zt=0.71165. We investigate the observational constraints on the model and calculate some relevant cosmological parameters. We examine the model’s validity by drawing state-finder parameters that yield the result compatible with the modern observational data. The model’s physical and geometrical characteristics are also explored, and they are shown to match well with current observations of observational Hubble data (OHD) and the latest joint light curves(JLA) datasets.

Multi-Messenger Constraints on the Hubble Constant through Combination of Gravitational Waves, Gamma-Ray Bursts and Kilonovae from Neutron Star Mergers

The simultaneous detection of gravitational waves and light from the binary neutron star merger GW170817 led to independent measurements of distance and redshift, providing a direct estimate of the Hubble constant H0 that does not rely on a cosmic distance ladder, nor assumes a specific cosmological model. By using gravitational waves as “standard sirens”, this approach holds promise to arbitrate the existing tension between the H0 value inferred from the cosmic microwave background and those obtained from local measurements. However, the known degeneracy in the gravitational-wave analysis between distance and inclination of the source led to a H0 value from GW170817 that was not precise enough to resolve the existing tension. In this review, we summarize recent works exploiting the viewing-angle dependence of the electromagnetic signal, namely the associated short gamma-ray burst and kilonova, to constrain the system inclination and improve on H0. We outline the key ingredients of the different methods, summarize the results obtained in the aftermath of GW170817 and discuss the possible systematics introduced by each of these methods.

Mirror twin Higgs cosmology: constraints and a possible resolution to the H0 and S8 tensions

The mirror twin Higgs model (MTH) is a solution to the Higgs hierarchy problem that provides well-predicted cosmological signatures with only three extra parameters: the temperature of the twin sector, the abundance of twin baryons, and the vacuum expectation value (VEV) of twin electroweak symmetry breaking. These parameters specify the behavior of twin radiation and the acoustic oscillations of twin baryons, which lead to testable effects on the cosmic microwave background (CMB) and large-scale structure (LSS). While collider searches can only probe the twin VEV, through a fit to cosmological data we show that the existing CMB (Planck18 TTTEEE+lowE+lowT+lensing) and LSS (KV450) data already provide useful constraints on the remaining MTH parameters. Additionally, we show that the presence of twin radiation in this model can raise the Hubble constant H0 while the scattering twin baryons can reduce the matter fluctuations S8, which helps to relax the observed H0 and S8 tensions simultaneously. This scenario is different from the typical ΛCDM + ∆Neff model, in which extra radiation helps with the Hubble tension but worsens the S8 tension. For instance, when including the SH0ES and 2013 Planck SZ data in the fit, we find that a universe with ≳ 20% of the dark matter comprised of twin baryons is preferred over ΛCDM by ∼ 4σ. If the twin sector is indeed responsible for resolving the H0 and S8 tensions, future measurements from the Euclid satellite and CMB Stage 4 experiment will further measure the twin parameters to O(1 − 10%)-level precision. Our study demonstrates how models with hidden naturalness can potentially be probed using precision cosmological data.

How to Relieve the Hubble Constant Tension? (Earth´s Gravitational Redshift + Earth´s Diurnal Aberration)

There were published very precise experimental values of the Hubble constant H0 in the range 66 -74 km/s/Mpc during the last decade. There is a very active discussion in the H0 community how to relieve this Hubble constant tension. In our model we have described the cosmological redshift as the expansion of old photons in the Earth´s gravitational field: the joint effect of the Earth´s gravitational redshift and the Earth´s diurnal aberration. This model predicts the value of the Hubble constant on the surface of the Earth EARTHH0 = 66.71 km/s/Mpc and on the board of the Hubble Space Telescope (HST) HSTH0 = 72.34 km/s/Mpc. The value H0 determines the expansion of old photons in the Earth´s gravitational field and not the age of the Universe or the age of that old photon. In order to falsify this model in the spirit of Karl Popper we predict the value of H0 for the surface of the Moon as MOONH0 = 6.62 km/s/Mpc. This experiment for the determination of the value H0 on the Moon´s surface is technically possible with the existing technology during this decade while several advanced countries have plans to realize experiments on the surface of the Moon. This proposed experiment on the surface of the Moon might open a new epoch in the description of our cosmological models.

Modified Equations of State for Dark Energy and Observational Limitations

Cosmological models with variable and modified equations of state for dark energy are confronted with observational data, including Type Ia supernovae, Hubble parameter data H(z) from different sources, and observational manifestations of cosmic microwave background radiation (CMB). We consider scenarios generalizing the ΛCDM, wCDM, and Chevallier–Polarski–Linder (CPL) models with nonzero curvature and compare their predictions. The most successful model with the dark energy equation of state w=w0+w1(1−a2)/2 was studied in detail. These models are interesting in possibly alleviating the Hubble constant H0 tension, but they achieved a modest success in this direction with the considered observational data.

An 8 per cent determination of the Hubble constant from localized fast radio bursts

ABSTRACT The cosmological-constant (Λ) cold dark matter (CDM) model is challenged by the Hubble tension, a remarkable difference of Hubble constant H0 between measurements from local probes and the prediction from Planck cosmic microwave background observations under ΛCDM model. So one urgently needs new distance indicators to test the Hubble tension. Fast radio bursts (FRBs) are millisecond-duration pulses occurring at cosmological distances, which are attractive cosmological probes. Here, we report a measurement of ${H_0} = 68.81^{+4.99}_{-4.33} {\rm \ km \ s^{-1} \ Mpc^{-1}}$ using eighteen localized FRBs, with an uncertainty of 8 per cent at 68.3 per cent confidence. Using a simulation of 100 localized FRBs, we find that error of H0 can be reduced to 2.6 per cent at 1σ uncertainty. Thanks to the high event rate of FRBs and localization capability of radio telescopes (i.e. Australian Square Kilometre Array Pathfinder and Very Large Array), future observations of a reasonably sized sample will provide a new way of measuring H0 with a high precision to test the Hubble tension.

Toward a Better Understanding of Cosmic Chronometers: A New Measurement of H(z) at z ∼ 0.7

Abstract We analyze the stellar ages obtained from a combination of Lick indices in Borghi et al. for 140 massive and passive galaxies selected in the LEGA-C survey at 0.6 < z < 0.9. From their median age–redshift relation, we derive a new direct measurement of H(z) without any cosmological model assumption using the cosmic chronometer approach. We thoroughly study the main systematics involved in this analysis: the choice of the Lick indices combination, the binning method, the assumed stellar population model, and the adopted star formation history; these effects are included in the total error budget. We obtain H(z = 0.75) = 98.8 ± 33.6 km s−1 Mpc−1. In parallel, we also propose a simple framework based on a cosmological model to describe the age–redshift relations in the context of galaxy downsizing. This allows us to derive constraints on the Hubble constant H 0 and the typical galaxy formation time. This new H(z) measurement, whose accuracy is currently limited by the scarcity of the sample analyzed, paves the road for the joint study of the stellar populations of individual passive galaxies and the expansion history of the universe in light of future spectroscopic surveys.