Related papers: Observational Challenges for the Standard FLRW Mod…
This paper investigates the flat Friedmann-Lema$\hat{\imath}$tre-Robertson-Walker (FLRW) cosmological model using a suitable parameterization represented as a differential equation concerning the energy density of the scalar field,…
We explore transformations of the Friedman-Lema\^itre-Robertson-Walker (FLRW) metric and cosmological parameters that align with observational data, aiming to gain insights into potential extensions of standard cosmological models. We…
Distance--redshift relations are given in terms of associated Legendre functions for partially filled beam observations inspatially flat Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmologies. These models are dynamically pressure-free,…
Fock space quantization of Hamiltonian constraints of General Relativity and thermodynamics of quantum states for flat Friedmann-Lemaitre-Robertson-Walker metrics is presented.
We consider the general scalar field Horndeski Lagrangian coupled to matter. Within this class of models, we present two results that are independent of the particular form of the model. First, we show that in a Friedmann-Robertson-Walker…
We present a new test of the validity of the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric, based on comparing the distance from redshift 0 to $z_1$ and from $z_1$ to $z_2$ to the distance from $0$ to $z_2$. If the universe is described…
It has been proposed that the observed dark energy can be explained away by the effect of large-scale nonlinear inhomogeneities. In the present paper we discuss how observations constrain cosmological models featuring large voids. We start…
We show that modelling the universe as a pre-geometric system with emergent quantum modes, and then constructing the classical limit, we obtain a new account of space and gravity that goes beyond Newtonian gravity even in the…
This article reviews an approach for constructing a simple relativistic fractal cosmology whose main aim is to model the observed inhomogeneities of the distribution of galaxies by means of the Lemaitre-Tolman solution of Einstein's field…
We construct a compact phase space for flat FLRW spacetimes with standard matter described by a perfect fluid with a barotropic equation of state for general f(R) theories of gravity, subject to certain conditions on the function f. We then…
Scalar field cosmologies with a generalized harmonic potential and a matter fluid with a barotropic Equation of State (EoS) with barotropic index $\gamma$ for the Locally Rotationally Symmetric (LRS) Bianchi I and flat…
The relativistic Friedmann Lemaitre cosmology model (FLCM) is very sucessful to describe the evolution history of the Universe from the " First three Minutes". Any alternative model should be consistent with the FLCM explanations to the…
We consider general-relativistic rotational perturbations in homogeneous and isotropic Friedman - Robertson - Walker (FRW) cosmologies. Taking linear perturbations of FRW models, the general solution of the field equations contains…
The assumption of a Friedmann-Lema\^itre-Roberton-Walker (FLRW) Universe is one of the fundamental pillars of modern Cosmology. It is crucial to confront it against cosmological observations in order to confirm (or rule out) the validity of…
We briefly review some constraints (Owing to the limited number of pages of present review, only a sub-sample of the topics discussed during the talk are briefly summarized. For the interested readers we are pleased to send them upon…
Considering the physical 3-space t = constant of the spacetime metrics as spheroidal and pseudo spheroidal, cosmological models which are generalizations of Robertson-Walker models are obtained. Specific forms of these general models as…
In this paper, we study a cosmological model in general relativity within the framework of spatially flat Friedmann-Robertson-Walker space-time filled with ordinary matter (baryonic), radiation, dark matter and dark energy, where the latter…
In this paper within the scope of FRW cosmology for k = 0, \pm1 we study the dynamics of the universe for a cosmological model with a scalar field nonminimally coupled to matter. By best- fitting the model parameters with the observational…
In view of new experimental results that strongly suggest a non-zero cosmological constant, it becomes interesting to revisit the Friedman-Lemaitre model of evolution of a universe with cosmological constant and radiation pressure. In this…
In this article we have presented FRW cosmological model in the framework of Brans-Dicke theory. This paper deals with a new proposed form of deceleration parameter and cosmological constant. The effect of bulk viscosity is also studied in…