Related papers: Observational constraints on noncold dark matter a…
The nature of dark matter remains one of the most fundamental and unresolved questions in modern cosmology. In most cosmological models, dark matter is typically modeled as pressureless dust with an equation of state (EoS) parameter $w_{\rm…
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.…
While cold dark matter is widely supported by a range of cosmological observations, it encounters several difficulties at smaller scales. These issues have prompted the investigation of various alternative dark matter candidates, leaving…
In this work we examine the recently proposed phenomenological emergent dark energy (PEDE) model by \cite{Li:2019yem}, using the latest observational data in both expansion and perturbation levels. Applying the statistical Bayesian evidence…
Motivated by the current status of the cosmological observations and significant tensions in the estimated values of some key parameters assuming the standard $\Lambda$CDM model, we propose a simple but radical phenomenological emergent…
We introduce a modified form of the Phenomenologically Emergent Dark Energy (PEDE) model by showing a very elegant approach. The model is named as Modified Emergent Dark Energy (MEDE) to distinguish from PEDE model and it includes…
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…
Recent cosmological observations show a statistically significant tension in the estimated values of the cosmological parameters within the standard $\Lambda$CDM framework. In a recent study, Li and Shafieloo introduced a simple…
We introduce a generalised form of an emergent dark energy model with one degree of freedom for the dark energy sector that has the flexibility to include both $\Lambda$CDM model as well as the Phenomenologically Emergent Dark Energy (PEDE)…
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 ($w_{\rm dm}$),…
Cold New Early Dark Energy (Cold NEDE) addresses the Hubble tension through a triggered vacuum phase transition in the dark sector. In this paper, we constrain a phenomenological fluid model using recent cosmic microwave background…
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…
The phenomenologically emergent dark energy (PEDE) model is a varying dark energy model with no extra degrees of freedom proposed by Li and Shafieloo\citep{Li_2019} to alleviate the Hubble tension. The statistical consistency of the model…
The Hubble tension persists as a challenge in cosmology. Even early dark energy (EDE) models, initially considered the most promising for alleviating the Hubble tension, fall short of addressing the issue without exacerbating other…
We investigate a generalized form of the phenomenologically emergent dark energy model, known as generalized emergent dark energy (GEDE), introduced by Li and Shafieloo [Astrophys. J. {\bf 902}, 58 (2020)] in light of a series of…
The Phenomenologically Emergent Dark Energy model, a dark energy model with the same number of free parameters as the flat $\Lambda$CDM, has been proposed as a working example of a minimal model which can avoid the current cosmological…
Comprehensive cosmological analysis of an effective non-standard dark matter(NSDM) model, characterized by an equation of state $w_{\mathrm{dm}} = w_2 a^2$, which allows for mild deviations from the previously assumed pressureless cold dark…
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…
The early dark energy (EDE) extension to $\Lambda$CDM has been proposed as a candidate scenario to resolve the "Hubble tension". We present new constraints on the EDE model by incorporating new data from the Dark Energy Spectroscopic…
In this work, we investigate the phenomenologically emergent dark energy (PEDE) model and its generalized form, namely the generalized emergent dark energy (GEDE) model, which introduces a free parameter \unboldmath {\( \Delta \)} that can…