相关论文: New Early Dark Energy as a solution to the $H_0$ a…
Simple models are constructed for "acceleressence" dark energy: the latent heat of a phase transition occurring in a hidden sector governed by the seesaw mass scale v^2/M_Pl, where v is the electroweak scale and M_Pl the gravitational mass…
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…
The $\Lambda$ Cold Dark Matter model ($\Lambda$CDM) represents the current standard model in cosmology. Within this, there is a tension between the value of the Hubble constant, $H_0$, inferred from local distance indicators and the angular…
Current tensions in cosmology, including $H_0$ and $\sigma_8$, provide one of the strong reasons to suspect the existence of physics beyond the standard model of cosmology ($\Lambda$CDM). In this paper, we investigate if there is a relation…
Early dark energy (EDE) is an extension to the $\Lambda$CDM model, proposed to reduce the tension between the measurements of the Hubble constant $H_0$ from the cosmic microwave background (CMB) and from the local cosmic distance ladder.…
In this study, cosmological models are considered, where dark matter and dark energy are coupled and may exchange energy through non-gravitational interactions with one other. These interacting dark energy (IDE) models have previously been…
This paper introduces the class of omnipotent dark energy (DE) models characterized by nonmonotonic energy densities that are capable of attaining negative values with corresponding equation of state parameters featuring phantom divide line…
The tension between the value of the Hubble constant $H_0$ determined from local supernovae data and the one inferred from the cosmic microwave background based on the $\Lambda$CDM cosmological model may indicate the need for new physics.…
We investigate a specific emergent dark energy scenario, known as critically emergent dark energy (CEDE), in which dark energy is effectively absent in the early Universe and becomes dynamically relevant only after a critical cosmic epoch…
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,…
We present a novel source of dark energy, which is motivated by the prevalence of hidden sectors in string theory models and is consistent with all of the proposed swampland conjectures. Thermal effects hold a light hidden sector scalar at…
The emergence of an increasingly strong tension between the Hubble rate inferred from early- and late-time observations has reinvigorated interest in nonstandard scenarios, with the aim of reconciling these measurements. One such model…
In this paper, we introduce two coupling models of early dark energy (EDE) and cold dark matter aimed at alleviating cosmological tensions. We utilize the EDE component in the coupling models to relieve the Hubble tension, while leveraging…
We study the possibility of Late Forming Dark Matter (LFDM), where a scalar field, previously trapped in a metastable state by thermal or finite density effects, begins to oscillate near the era matter-radiation equality about its true…
Recent interest in New Early Dark Energy (NEDE), a cosmological model with a vacuum energy component decaying in a triggered phase transition around recombination, has been sparked by its impact on the Hubble tension. Previous constraints…
We investigate a cosmological model wherein a waterfall symmetry breaking occurs during the radiation-dominated era. The model comprises a complex waterfall field, an axion field, and the gauge field (dark photon) generated through a…
The mystery of the Dark energy is not just its smallness. The extreme fine tuning of its density in the Early Universe such that it permits galaxy formation before creating a new inflationary epoch is its other unexplained aspect. Here we…
We propose a new coupled three-form dark energy model to relieve the Hubble tension in this paper. Firstly, by performing a dynamical analysis with the coupled three-form dark energy model, we obtain four fixed points, including a saddle…
The today estimated value of dark energy can be achieved by the vacuum condensate induced by neutrino mixing phenomenon. Such a tiny value is recovered for a cut-off of the order of Planck scale and it is linked to the sub eV neutrino mass…
Persistent tensions in the Hubble constant (H0) and the matter clustering parameter (S8) motivate late-time new physics that suppresses structure growth without significantly altering the background expansion history of the LambdaCDM model.…