Two-field axion-like early dark energy reduces Hubble tension to 1.5 sigma residual and improves high-ell CMB fits over single-field models.
G´ omez-Valent,Fast test to assess the impact of marginalization in Monte Carlo analyses and its application to cosmology, Phys
6 Pith papers cite this work. Polarity classification is still indexing.
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abstract
Monte Carlo (MC) algorithms are commonly employed to explore high-dimensional parameter spaces constrained by data. All the statistical information obtained in the output of these analyses is contained in the Markov chains, which one needs to process and interpret. The marginalization technique allows us to digest these chains and compute the posterior distributions for the parameter subsets of interest. In particular, it lets us draw confidence regions in two-dimensional planes, and get the constraints for the individual parameters. It is very well known, though, that the marginalized results can suffer from volume effects, which can introduce a non-negligible bias into our conclusions. The impact of these effects are barely studied in the literature. In this paper we first illustrate the problem through a very clear and simple example in two dimensions, and suggest the use of the profile distributions (PDs) as a complementary tool to detect marginalization biases directly from the MC chains. We apply our method to four cosmological models: the standard $\Lambda$CDM, early dark energy, coupled dark energy and the Brans-Dicke model with a cosmological constant. We discuss the impact of the volume effects on each model and the cosmological tensions, using the full Planck 2018 likelihood, the Pantheon compilation of supernovae of Type Ia and data on baryon acoustic oscillations. Our test is very efficient and can be easily applied to any MC study. It allows us to estimate the PDs at a derisory computational cost not only for the main cosmological parameters, but also for the nuisance and derived ones, and to assess the need to perform a more in-depth analysis with the exact computation of the PDs.
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DESI DR1 full-shape galaxy clustering constrains Omega_m = 0.296 ± 0.010, H0 = 68.63 ± 0.79 km/s/Mpc, and sigma_8 = 0.841 ± 0.034, consistent with LambdaCDM and Planck.
Under standard recombination, phantom-crossing dynamical dark energy is preferred at ~97–98.5% probability; early-time fixes to the Hubble tension erase that preference while creating severe ω_m tension with CMB.
Halo reconstruction from redshift-space galaxies allows unbiased EFT full-shape inference with >20% tighter fσ8 constraints and stable results to smaller scales on DESI mocks.
A swampland-inspired DM-EDE coupling is tested against DESI DR2 BAO data, showing the EDE potential construction affects late-time dark energy constraints.
DESI DR1 constrains the modified gravity parameter to log10 |f_R0| < -4.59 at 95% CL, implying no detectable fifth force on scales below about 18 Mpc.
citing papers explorer
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Double the axions, half the tension: multi-field early dark energy eases the Hubble tension
Two-field axion-like early dark energy reduces Hubble tension to 1.5 sigma residual and improves high-ell CMB fits over single-field models.
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DESI 2024 V: Full-Shape Galaxy Clustering from Galaxies and Quasars
DESI DR1 full-shape galaxy clustering constrains Omega_m = 0.296 ± 0.010, H0 = 68.63 ± 0.79 km/s/Mpc, and sigma_8 = 0.841 ± 0.034, consistent with LambdaCDM and Planck.
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Exploring the interplay of late-time dynamical dark energy and new physics before recombination
Under standard recombination, phantom-crossing dynamical dark energy is preferred at ~97–98.5% probability; early-time fixes to the Hubble tension erase that preference while creating severe ω_m tension with CMB.
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Cosmological inference with halo clustering reconstructed from the redshift-space galaxy distribution
Halo reconstruction from redshift-space galaxies allows unbiased EFT full-shape inference with >20% tighter fσ8 constraints and stable results to smaller scales on DESI mocks.
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Imprint of swampland-inspired coupled early dark energy
A swampland-inspired DM-EDE coupling is tested against DESI DR2 BAO data, showing the EDE potential construction affects late-time dark energy constraints.
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Testing Scale-Dependent Modified Gravity with DESI DR1
DESI DR1 constrains the modified gravity parameter to log10 |f_R0| < -4.59 at 95% CL, implying no detectable fifth force on scales below about 18 Mpc.