Related papers: Dark Energy and Matter Evolution from Lensing Tomo…
We review the current state of the theory of large scale structure in a warm dark matter (WDM) cosmological model. In particular, we focus on the non-linear modelling of the matter power spectrum and on the mass function of dark matter…
When using distance measurements to probe spatial curvature, the geometric degeneracy between curvature and dark energy in the distance-redshift relation typically requires either making strong assumptions about the dark energy evolution or…
We propose a logarithmic parametrization form of energy density for the scalar field dark energy in the framework of the standard theory of gravity, which supports the necessary transition from the decelerated to the accelerated behavior of…
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…
Despite evidence for the existence of dark matter (DM) from very high and low redshifts, a moderate amount of DM particle decay remains a valid possibility. This includes both models with very long-lived yet unstable particles or mixed…
We study structure formation in alternative cosmological models constrained by background observations, including $\Lambda$CDM, wCDM, the Chevallier-Polarski-Linder parametrisation and a flexible Chebyshev expansion of the dark energy…
We propose that dark matter (DM) possesses a quadratic equation of state, which becomes significant at high densities, altering the Universe's evolution during its early stages. We derive the modified background evolution equations for the…
While dark energy has dominated cosmic dynamics only since $z\approx0.7$, its energy density was still $\gtrsim5\%$ of the total out to $z\approx2.5$. We calculate model independent constraints on its fraction from future galaxy surveys,…
Astronomical measurements of the Omegas for mass density, cosmological constant lambda and curvature k are shown to be sufficient to produce a unique and detailed cosmological model describing dark energy influences based on the Friedman…
We study the dynamical aspects of dark energy in the context of a non-minimally coupled scalar field with curvature and torsion. Whereas the scalar field acts as the source of the trace mode of torsion, a suitable constraint on the torsion…
We have found a mechanism which regulates the dark energy in our universe. With an emergent conformal symmetry, the dark energy density is regulated to the order of a conformal anomaly parameter in the conformally coupled gravity. In the…
We find that if we live at the center of an inhomogeneity with total density contrast of roughly 0.1, dark energy is not a cosmological constant at 95% confidence level. Observational constraints on the equation of state of dark energy, w,…
We perform parametric tests of the consistency of the standard $w$CDM model in the framework of general relativity by carefully separating information between the geometry and growth of structure. We replace each late-universe parameter…
We study the evidence for dark energy (DE) evolution at low redshift, using baryonic acoustic oscillations (BAOs) from the DESI Early Data Release, Pantheon+ Type Ia supernovae (SNe-Ia), and redshift space distortions (RSDs) to constrain…
We investigate the possibility of a dark energy component that is scaling with epochs. A phenomenological model is introduced whose energy density depends on the redshift in such a way that a smooth transition among the three dominant…
It has recently been shown that the observed Hubble function for cosmological expansion can be fitted accurately back to redshift unity (7.33 Gyr ago) with only one free constant, while neglecting cosmic curvature and mass, using the…
We look for evidence for the evolution in dark energy density by employing Principal Component Analysis (PCA). Distance redshift data from supernovae and baryon acoustic oscillations (BAO) along with WMAP7 distance priors are used to put…
A new parameterization for the dark energy equation of state(EoS) is proposed and some of its cosmological consequences are also investigated. This new parameterization is the modification of Efstathiou' dark energy EoS parameterization. $w…
A type of exponential correction to General Relativity gives viable modified gravity model of dark energy. The model behaves as $R-2\Lambda$ at large curvature where an effective cosmological constant appears, but it becomes zero in flat…
This review summarizes recent attempts to reconstruct the expansion history of the Universe and to probe the nature of dark energy. Reconstruction methods can be broadly classified into parametric and non-parametric approaches. It is…