Related papers: Early Dark Energy beyond slow-roll: implications f…

Early dark energy, an additional component of dark energy active in the decade of redshift before recombination, has emerged as one of the most effective models at reducing the $H_0$ tension between direct measurement of the Hubble…

In this paper we explore the existing tensions in the local cosmological expansion rate, $H_0$, and amplitude of the clustering of large-scale structure at $8\, h^{-1}\mathrm{Mpc}$, $\sigma_8$, as well as models that claim to alleviate…

I review and discuss the possible implications for inflation resulting from considering new physics in light of the Hubble tension. My study is motivated by a simple argument that the constraints on inflationary parameters, most typically…

New measurements of the expansion rate of the Universe have plunged the standard model of cosmology into a severe crisis. In this letter, we propose a simple resolution to the problem that relies on a first order phase transition in a dark…

The idea of neutrino-assisted early dark energy ($\nu$EDE), where a coupling between neutrinos and the scalar field that models early dark energy (EDE) is considered, was introduced with the aim of reducing some of the fine-tuning and…

We investigate several phenomenological dark energy parameterizations using a joint analysis of late-time cosmological observations, including cosmic-chromatometer measurements of the Hubble parameter, DESI DR2 baryon acoustic oscillation…

We study the performance of the spatially-flat dynamical dark energy (DE) $w_0w_a$CDM parameterization, with redshift-dependent DE fluid equation of state parameter $w(z) = w_0 + w_a z/(1+z)$, with and without a varying CMB lensing…

We propose a novel parameterization of the dark energy density. It is particularly well suited to describe a non-negligible contribution of dark energy at early times and contains only three parameters, which are all physically meaningful:…

Early dark energy (EDE) models have attracted attention in the context of the recent problem of the Hubble tension. Here we extend these models by taking into account the new density fluctuations generated by the EDE which decays around the…

A dark energy-like component in the early universe, known as early dark energy (EDE), is a proposed solution to the Hubble tension. Currently, there is no consensus in the literature as to whether EDE can simultaneously solve the Hubble…

We examine the validity of the $\Lambda$CDM model, and probe for the dynamics of dark energy using latest astronomical observations. Using the $Om(z)$ diagnosis, we find that different kinds of observational data are in tension within the…

We propose a new cosmological model that considers dark matter as a barotropic fluid with a constant equation of state parameter and interprets dark energy as the phenomenological emergent dark energy rather than a cosmological constant.…

We investigate constraints on early dark energy (EDE) using ACT DR4, SPT-3G 2018, Planck polarization, and restricted Planck temperature data (at $\ell<650$), finding a $3.3\sigma$ preference ($\Delta\chi^2=-16.2$ for 3 additional degrees…

Dark energy (DE) models with many free parameters are often considered excessive, as constraining all parameters poses a significant challenge. While such models offer greater flexibility to probe the DE sector in more detail. With the…

New Early Dark Energy (NEDE) is a component of vacuum energy at the electron volt scale, which decays in a first-order phase transition shortly before recombination [arXiv:1910.10739]. The NEDE component has the potential to resolve the…

We study dynamical dark energy models that allow for general late time behaviour while admitting non-phantom dynamics at early times, including thawing, scaling$+$thawing, and effective fluid extensions. Using current cosmological data, we…

High precision cosmological observations in last decade suggest that about 70% of our universe's energy density is in so called "Dark Energy" (DE). Observations show that DE has negative effective pressure and therefore unlike conventional…

Measurements of the current expansion rate of the Universe, $H_0$, using standard candles, disagree with those derived from observations of the Cosmic Microwave Background (CMB). This discrepancy, known as the Hubble tension, is substantial…

In this study, we investigate the oscillatory dark energy model $w_{\sin}\mathrm{CDM}$ based on the DESI BAO data together with OHD, Pantheon Plus, and SH0ES measurements. We examine how the DESI data influence the dark energy…

In this paper, we investigate the kinetically coupled early dark energy (EDE) and scalar field dark matter to address cosmological tensions. The EDE model presents an intriguing theoretical approach to resolving the Hubble tension, but it…