Related papers: How isotropic is dark energy?
The possibility of constraining the parameters of scalar field dark energy with barotropic equation of state using different available datasets is discussed. It has been found that the initial value of dark energy equation of state…
The predicted present-day amplitude of matter fluctuations based on cosmic microwave background (CMB) anisotropy data has sometimes been found discrepant with more direct measurements of late-time structure. This has motivated many…
We study the dynamics of dark energy in the presence of a 2-form field coupled to a canonical scalar field $\phi$. We consider the coupling proportional to $e^{-\mu \phi/M_{\rm pl}} H_{\alpha \beta \gamma}H^{\alpha \beta \gamma}$ and the…
We perform a multiprobe analysis combining cosmic microwave background (CMB) data from Planck and the Atacama Cosmology Telescope (ACT), ACT CMB lensing, and large-scale structure (LSS) measurements from the Dark Energy Spectroscopic…
Detecting dark energy dynamics is the main quest of current dark energy research. Addressing the issue demands a fully consistent analysis of CMB, large scale structure and SN-Ia data with multi-parameter freedom valid for all redshifts.…
We present a comprehensive reassessment of the state of Interacting Dark Energy (IDE) cosmology, namely models featuring a non-gravitational interaction between Dark Matter (DM) and Dark Energy (DE). To achieve high generality, we extend…
We study a dark energy model with non-zero anisotropic stress, either linked to the dark energy density or to the dark matter density. We compute approximate solutions that allow to characterise the behaviour of the dark energy model and to…
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 ($w_{\rm dm}$),…
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…
The general form of the anisotropy parameter of the expansion for Bianchi type-III metric is obtained in the presence of a single diagonal imperfect fluid with a dynamically anisotropic equation of state parameter and a dynamical energy…
Recent results from the Dark Energy Spectroscopic Instrument (DESI) have shown a strong statistical preference for a time-evolving dark energy model over $\Lambda$CDM when combining BAO, CMB, and supernova (SN) data. We investigate the…
Measurements of time-delay cosmography of lensed quasars can provide an independent probe to explore the expansion history of the late-time Universe. In this paper, we employ the time-delay cosmography measurements from seven lenses (here…
Spatially homogeneous but totally anisotropic and non-flat Bianchi type II cosmological model has been studied in general relativity in the presence of two minimally interacting fluids; a perfect fluid as the matter fluid and a hypothetical…
The DESI collaboration have recently analyzed their first year of data, finding a preference for thawing dark energy scenarios when using parameterized equations of state for dark energy. We investigate whether this preference persists when…
Within the scope of an anisotropic Bianchi type-VI cosmological model we have studied the evolution of the universe filled with perfect fluid and dark energy. To get the deterministic model of Universe, we assume that the shear scalar…
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 general relativity, for fluids with a linear equation of state (EoS) or scalar fields, the high isotropy of the universe requires special initial conditions, and singularities are anisotropic in general. In the brane world scenario…
We investigate the consequences of an imperfect dark energy component on the large scale structure. A phenomenological three parameter fluid description is used to study the effect of dark energy on the cosmic microwave background radiation…
We determine constraints on spatially-flat tilted dynamical dark energy XCDM and $\phi$CDM inflation models by analyzing Planck 2015 cosmic microwave background (CMB) anisotropy data and baryon acoustic oscillation (BAO) distance…
In this study, we present observational constraints on a class of phenomenological interacting dark energy (IDE) models that admit analytical solutions for the Hubble parameter $H(z)$. We consider a set of five linear and three non-linear…