相关论文: Dark Matter Cosmology with Varying Viscosity: a Po…
We investigate the effects of viscosity terms depending on the Hubble parameter and its derivatives in the dark energy equation of state. Such terms are possible if dark energy is a fictitious fluid originating from corrections to the…
Models which address both the Hubble and $S_8$ tensions with the same mechanism generically cause a pre-recombination suppression of the small scale matter power spectrum. Here we focus on two such models. Both models introduce a…
The recent measurements of the cosmological parameter $H_0$ from the direct local observations and the inferred value from the Cosmic Microwave Background show $\sim 4 \sigma$ discrepancy. This may indicate new physics beyond the standard…
The introduction of Dark Matter-neutrino interactions modifies the Cosmic Microwave Background (CMB) angular power spectrum at all scales, thus affecting the reconstruction of the cosmological parameters. Such interactions can lead to a…
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 discuss the possibility to implement a viscous cosmological model, attributing to the dark matter component a behaviour described by bulk viscosity. Since bulk viscosity implies negative pressure, this rises the possibility to unify the…
Observations of the cosmic microwave background (CMB) together with weak lensing measurements of the clustering of large scale cosmological structures and local measurements of the Hubble constant pose a challenge to the standard…
I review the observational data most relevant for large scale structure. These data determine the system of cosmological parameters: the Hubble parameter, densities of various populations of the Universe, parameters characterizing the power…
The unified dark energy and dark matter model within the framework of a model of a continuous medium with bulk viscosity (dark fluid) is considered. It is supposed that the bulk viscosity coefficient is an arbitrary function of the Hubble…
A family of simple and minimal extensions of the standard cosmological $\Lambda$CDM model in which dark matter experiences an additional long-range scalar interaction is demonstrated to alleviate the long lasting Hubble-tension while…
We study cosmological perturbations in the context of an interacting dark energy model, in which the cosmological term decays linearly with the Hubble parameter, with concomitant matter production. A previous joint analysis of the…
In this talk I will review the current status of the constraints on the neutrino properties from cosmological measurements, with a particular focus on their mass and effective number. I will also discuss the existing tensions within the…
Decaying dark matter models generically modify the equation of state around the time of dark matter decay, and this in turn modifies the expansion rate of the Universe through the Friedmann equation. Thus, a priori, these models could solve…
In the present work, we study a cosmological model composed of a viscous dark matter interacting with decaying vacuum energy in a spatially flat Universe. In the first part, we find the analytical solution of different cosmological…
Based on the assumption that the dark energy possessing bulk viscosity is homogenously and isotropically permeated in the universe, we propose three new viscous dark energy (VDE) models to characterize the accelerating universe. By…
We study an expanding two-fluid model of non-relativistic dark matter and radiation which are allowed to interact during a certain time span and to establish an approximate thermal equilibrium. Such interaction which generates an effective…
The analytic properties of the energy density rho(t) of the cosmic fluid, and the Hubble parameter H(t), are investigated near to the future singularity t=t_s assuming different forms for the equation of state. First, it is shown that the…
The values of Hubble constant H0 by direct measurements with standard distance ladder are typically larger than those obtained from the observation of cosmic microwave background and the galaxy survey with inverse distance ladder. On the…
Early dark energy has emerged as one of the more promising approaches to address the Hubble tension - the statistically significant disparity between measurements of the Hubble constant made using data from different epochs in cosmic…
In this work, we study the extended viscous dark energy models in the context of matter perturbations. To do this, we assume an alternative interpretation of the flat Friedmann-Lema\^itre-Robertson-Walker Universe, through the nonadditive…