相关论文: Cosmological Observations in a Local Void
We have carefully studied how local measurements of the Hubble constant, $H_0$, can be influenced by a variety of different parameters related to survey geometry, depth, and size, as well as observer position in space. Our study is based on…
In this paper, we considered the study of Friedmann-Robertson-Walker (FRW) model in the framework of $f(Q,T)$ gravity, an extension of symmetric teleparallel gravity, recently defined by Y. Xu et al. \cite{Xu}. The non-linear model…
Do current observational data confirm the assumptions of the cosmological principle, or is there statistical evidence for deviations from spatial homogeneity on large scales? To address these questions, we developed a flexible framework…
We explore the large angular scale temperature anisotropies in the cosmic microwave background (CMB) due to homogeneous local dust-filled voids in a flat Friedmann-Robertson-Walker universe with a cosmological constant. In comparison with…
We consider the holographic Friedman-Robertson-Walker (hFRW) universe on the 4-dimensional membrane embedded in the 5-dimensional bulk spacetime and fit the parameters with the observational data. In order to fully account for the…
The increasing precision in the determination of the Hubble parameter has reached a per cent level at which large-scale cosmic flows induced by inhomogeneities of the matter distribution become non-negligible. Here we use large-scale…
We have considered a cosmological model of the FRW universe with variable $G$ and $\Lambda$. The solutions have been obtained for flat model with particular form of cosmological constant. The cosmological parameters have also been obtained…
We consider a flat cosmological model with a free massless scalar field and the cosmological constant $\Lambda$ in the framework of loop quantum cosmology. The scalar field plays the role of an intrinsic time. We apply the reduced phase…
Observational cosmology provides us with a large number of high precision data which are used to derive models trying to reproduce ``on the mean'' our observable patch of the Universe. Most of these attempts are achieved in the framework of…
In this methodological note we discuss several topics related to interpretation of some basic cosmological principles. We demonstrate that one of the key points is the usage of synchronous reference frames. The Friedmann-Robertson-Walker…
Forthcoming surveys will extend the understanding of cosmological large scale structures up to unprecedented redshift. According to this perspective, we present a fully relativistic framework to evaluate the impact of stochastic…
The existence of 'peculiar' velocities due to the formation of cosmic structure marks a point of discord between the real Universe and the usually assumed Friedmann-Lema\'{i}tre-Robertson-Walker metric which accomodates only the smooth…
We study some observational consequences of a recently proposed scale--dependent cosmological model for an inhomogeneous Universe. In this model the Universe is pictured as being inside a highly dense and rapidly expanding shell with the…
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…
The present matter density of the Universe, while highly inhomogeneous on small scales, displays approximate homogeneity on large scales. We propose that whereas it is justified to use the Friedmann-Lemaitre-Robertson-Walker (FLRW) line…
The dispersion measure-redshift relation of fast radio bursts (FRBs) provides a valuable cosmological probe for constraining the Hubble constant, offering an independent measurement that could help resolve the ongoing Hubble tension. In…
There is an approximately 9% discrepancy, corresponding to 2.4sigma, between two independent constraints on the expansion rate of the universe: one indirectly arising from the cosmic microwave background and baryon acoustic oscillations,…
The Robertson-Walker (RW) metric allows us to apply general relativity to model the behavior of the Universe as a whole (i.e., cosmology). We can properly interpret various cosmological observations, like the cosmological redshift, the…
This is the first paper of a series aiming at investigating galaxy formation and evolution in the giant-void class of the Lemaitre-Tolman-Bondi (LTB) models that best fits current cosmological observations. Here we investigate the…
We explore how local, cosmology-independent measurements of the Hubble constant and the age of the Universe help to provide a powerful consistency check of the currently favored cosmological model (flat LambdaCDM) and model-independent…