Related papers: The cosmological bulk flow in QCDM model: (In)cons…
The $\Lambda$ cold dark matter ($\Lambda$CDM) standard cosmological model is in severe tension with several cosmological observations. Foremost is the Hubble tension, which exceeds $5\sigma$ confidence. Galaxy number counts show the…
The standard formulation of General Relativity Theory, in the absence of a cosmological constant, is unable to explain the responsible mechanism for the observed late-time cosmic acceleration. On the other hand, by inserting the…
I review the recent developments in the analysis of cosmic flow data, in particular, latest results of bulk flow measurements, comparison between redshift and peculiar velocity catalogs with emphasis on the measured value of the $\beta…
While much of the focus of observational cosmology is on the high redshift universe it is important not to neglect the very local universe as a source of cosmological information. The inner profiles and number counts of low mass halos have…
The unexpected dimness of Type Ia supernovae at redshifts z >~ 1 has over the past 7 years been seen as an indication that the expansion of the universe is accelerating. A new model cosmology, the "fractal bubble model", has been proposed…
Bulk peculiar flows are commonplace in the universe, with many surveys reporting their presence on scales spanning between few hundred and several hundred Mpc. However, the sizes and the speeds of some of these bulk flows are well in excess…
The universe content is considered as a non-perfect fluid with bulk viscosity and can be described by a general equation of state (endowed some deviation from the conventionally assumed cosmic perfect fluid model). An explicitly bulk…
The concordance (LambdaCDM) model reproduces the main current cosmological observations assuming the validity of general relativity at all scales and epochs, the presence of cold dark matter, and of a cosmological constant, equivalent to a…
As an alternative explanation for the cosmic acceleration, $f(R)$ theories of gravity can predict an almost identical expansion history to standard $\Lambda$CDM, yet make very different predictions for the growth of cosmological structures.…
A perfect fluid, spatially flat cosmology in a $f(T)$ model, derived from a recently proposed general Born-Infeld type theory of gravity is studied. Four dimensional cosmological solutions are obtained assuming the equation of state…
The {\em bulk flow} in the Local Universe is a collective phenomenon due to the peculiar motions of matter structures, which, instead of moving in random directions, appears to follow an approximate dipole velocity flow. We apply a…
Peculiar velocity surveys have non-uniform spatial distributions of tracers, so that the bulk flow estimated from them does not correspond to that of a simple volume such as a sphere. Thus bulk flow estimates are generally not strictly…
Currently, a large amount of data implies that the matter constituents of the cosmological dark sector might be collisional. An attractive feature of such a possibility is that, it can reconcile dark matter (DM) and dark energy (DE) in…
Full sky surveys of peculiar velocity are arguably the best way to map the large scale structure out to distances of a few times 100 Mpc/h. Using the largest and most accurate ever catalog of galaxy peculiar velocities "Cosmicflows-2", the…
To explain the puzzling situation in the observed bulk flows on scales $\sim 150 h^{-1}$ Mpc ($H_0 = 100 h^{-1}$ km sec$^{-1}$ Mpc$^{-1}$), we consider the observational behavior of spherically symmetric inhomogeneous cosmological models,…
Bulk flow velocities are typically estimated in the idealised picture where observers are moving within a perfectly homogeneous and isotropic space-time. This picture is consistent within standard perturbation theory up to relativistic…
Observed galaxy luminosities (derived from redshifts) hold information on the large-scale peculiar velocity field in the form of spatially correlated scatter, which allows for bounds on bulk flows and the growth rate of matter density…
We explore the late time cosmological dynamics of the Universe within the framework of $f(Q,\mathcal{L}_{m})$ gravity by considering the specific form $f(Q, \mathcal{L}_m)=-Q+2\mathcal{L}_m+\gamma$. To describe the cosmic pressure…
We give a brief review of recent developments in the study of the large-scale velocity field of galaxies since the international workshop on Cosmic Flows held in July 1999 in Victoria, B.C. Peculiar velocities (PVs) yield a tight and unique…
A large bulk flow, which is in tension with the Lambda Cold Dark Matter ($\Lambda$CDM) cosmological model, has been observed. In this paper, we provide a physically plausible explanation of this bulk flow, based on the assumption that some…