Related papers: Virialization-induced curvature versus dark energy
Motivated by their potential role as dark matter, we study the cosmological evolution of light scalar and vector fields non-minimally coupled to gravity. Our focus is on a situation where the dominant contribution to the energy density…
In this paper we investigate the cosmological effects of modified gravity with string curvature corrections added to Einstein-Hilbert action in the presence of a dynamically evolving scalar field coupled to Riemann invariants. The scenario…
Since current challenges faced by $\Lambda$CDM might be hinting at new unravelled physics, here we investigate a plausible cosmological model where a vector field acts as source of dark energy. In particular, we examine whether an…
We perform three-dimensional numerical relativity simulations of homogeneous and inhomogeneous expanding spacetimes, with a view towards quantifying non-linear effects from cosmological inhomogeneities. We demonstrate fourth-order…
An important part of cosmological model fitting relies on correlating distance indicators of objects (for example type Ia supernovae) with their redshift, often illustrated on a Hubble diagram. Comparing the observed correlation with a…
Constraints on the expansion history of the universe from measurements of cosmological distances make predictions for large-scale structure growth. Since these predictions depend on assumptions about dark energy evolution and spatial…
In this paper we investigate the evolution of the viscous dark energy (DE) interacting with the dark matter (DM) in the Einstein cosmology model. Using the linearizing theory of the dynamical system, we find, in our model, there exists a…
Two recently proposed techniques, involving the measurement of the cosmic parallax and redshift drift, provide novel ways of directing probing (over a time-span of several years) the background metric of the universe and therefore shed…
We examine a cosmological model with a dark energy density of the form $\rho_{DE}(t)=\rho_X(t)+\rho_Z(t)$, where $\rho_X$ is the component that accelerates the Hubble expansion at late times and $\rho_Z(t)$ is an extra contribution…
We investigate various dark energy models by taking into account the thermal effects induced from Hawking radiation on the apparent horizon of the Universe, for example near a finite-time future singularity. If the dark energy density…
In this work we explore under a holographic approach the dark energy - dark matter interaction in a non-flat Friedmann-Lemaitre-Robertson-Walker spacetime, with a cut-off for the dark energy component given in terms of the Hubble scale.…
We develop an approach to compute observables beyond the linear regime of dark matter perturbations for general dark energy and modified gravity models. We do so by combining the Effective Field Theory of Dark Energy and Effective Field…
Assuming the universe is spatially homogeneous on the largest scales lays the foundation for almost all cosmology. This idea is based on the Copernican principle, that we are not at a particularly special place in the universe.…
The observed cosmic acceleration today could be due to an unknown energy component (dark energy), or a modification to general relativity (modified gravity). If dark energy models and modified gravity models are required to predict the same…
We study the late-time evolution of the Universe where dark energy (DE) is presented by a barotropic fluid on top of cold dark matter (CDM). We also take into account the radiation content of the Universe. Here by the late stage of the…
This article looks at how inhomogeneous spacetime models may be significant for cosmology. First it looks at how the averaging process may affect large scale dynamics, with backreaction effects leading to effective contributions to the…
The $\Lambda$CDM cosmological model faces increasingly significant and robust tensions among independent cosmological probes, prompting renewed scrutiny of its foundational assumptions. While General Relativity and the nature of dark energy…
A simple speed-up cosmology model is proposed to account for the dark energy puzzle. We condense contributions from dark energy and curvature term into one effective parameter in order to reduce parameter degeneracies and to find any…
Over the past decade, the disparity between the value of the cosmic expansion rate directly determined from measurements of distance and redshift or instead from the standard $\Lambda$CDM cosmological model calibrated by measurements from…
We give a well-motivated explanation for the origin of dark energy, claiming that it arises from a small residual negative scalar-curvature present even in empty spacetime. The vacuum has this residual curvature because spacetime is…