Related papers: The $H_0$ and $S_8$ tensions necessitate early and…
We investigate constraints on some key cosmological parameters by confronting metastable dark energy models with different combinations of the most recent cosmological observations. Along with the standard $\Lambda$CDM model, two…
In recent years discrepancies have emerged in measurements of the present-day rate of expansion of the universe $H_0$ and in estimates of the clustering of matter $S_8$. Using the most recent cosmological observations we reexamine a novel…
This study investigates the potential of a cosmological model termed $\Lambda w$DM, in which a cosmological constant play the role of dark energy and dark matter is barotropic and has a constant equation of state parameter ($w_{\rm dm}$),…
Neutrinos and dark matter (DM) are two of the least understood components of the Universe, yet both play crucial roles in cosmic evolution. Clues about their fundamental properties may emerge from discrepancies in cosmological measurements…
In this work, we show that the Cold New Early Dark Energy (Cold NEDE) model in its original form can solve both the Hubble tension and the $S_8$ tension without adding any new ingredients at the fundamental level. So far, it was assumed…
Addressing the discrepancy between the late and early time measurements of the Hubble parameter, $H_0$, and the so-called $S_8$ parameter has been a challenge in precision cosmology. Several models are present to address these tensions, but…
Recently the Dark Energy Spectroscopic Instrument (DESI) provided constraints on the expansion history from their Data Release 2 (DR2). The DESI baryon acoustic oscillation (BAO) measurements are well described by a flat $\Lambda$CDM model,…
Models which address both the Hubble and $S_8$ tensions with the same mechanism generically cause a pre-recombination suppression of the small scale matter power spectrum. Here we focus on two such models. Both models introduce a…
We investigate the viability of $f(Q)$ gravity as an alternative framework to address the $H_0$ and $S_8$ tensions in cosmology. Focusing on three representative $f(Q)$ models, we perform a comprehensive Bayesian analysis using a…
Many late time approaches for the solution of the Hubble tension use late time smooth deformations of the Hubble expansion rate $H(z)$ of the Planck18/$\Lambda$CDM best fit to match the locally measured value of $H_0$ while effectively…
We present a further observational analysis of the $\Lambda_{\rm s}$CDM model proposed in Akarsu et al. [Phys. Rev. D 104, 123512 (2021)]. This model is based on the recent conjecture suggesting the Universe has transitioned from anti-de…
Despite the remarkable success of the $\Lambda$Cold Dark Matter ($\Lambda$CDM) cosmological model, a growing discrepancy has emerged (currently measured at the level of $\sim 4-6 \sigma$) between the value of the Hubble constant $H_0$…
The standard cosmological model currently in force, aka $\Lambda$CDM, has been plagued with a variety of tensions in the last decade or so, which puts it against the wall. At the core of the $\Lambda$CDM we have a rigid cosmological term,…
We investigate a cosmological model inspired by hybrid inflation, where two scalar fields representing dark energy (DE) and dark matter (DM) interact through a coupling that is proportional to the DE scalar field $1/\phi$. The strength of…
Currently, the standard cosmological model faces some tensions and discrepancies between observations at early and late cosmological time. One of them concerns the well-known $H_0$-tension problem, i.e., a $\sim4.4\sigma$-difference between…
We perform a comprehensive analysis of the most common early- and late-Universe solutions to the $H_0$, Ly-$\alpha$, and $S_8$ discrepancies. When considered on their own, massive neutrinos provide a natural solution to the $S_8$…
We propose a cosmological scenario in which, beyond matter and radiation, an additional barotropic fluid with positive equation of state $\omega_s$ contributes to the cosmic energy budget, in contrast to Early Dark Energy (EDE). We…
The $\Lambda$CDM model provides an excellent fit to the CMB data. However, a statistically significant tension emerges when its determination of the Hubble constant $H_0$ is compared to the local distance-redshift measurements. The…
We show that the $H_0$ tension can be resolved by making recombination earlier, keeping the fit to cosmic microwave background (CMB) data almost intact. We provide a suite of general necessary conditions to give a good fit to CMB data while…
In recent years, Cosmic Microwave Background (CMB) observations, Weak Lensing surveys, and $f\sigma_8(z)$ measurements from Redshift-Space Distortions (RSD) have revealed a significant ($\sim$3$-$5$\sigma$) discrepancy in the inferred value…