Related papers: Analyzing the Large-Scale Bulk Flow using CosmicFl…
In the standard (LCDM) model of cosmology the universe has emerged out of an early homogeneous and isotropic phase. Structure formation is associated with the growth of density irregularities and peculiar velocities. Our Local Group is…
Recent surveys seem to support bulk peculiar velocities well in excess of those anticipated by the standard cosmological model. In view of these results, we consider here some of the theoretical implications of large-scale drift motions. We…
Recent measurements of large-scale peculiar velocities from the cumulative kinematic Sunyaev-Zel'dovich effect using WMAP data and X-ray selected clusters from ROSAT have identified a bulk flow of galaxy clusters at $\sim 600-1,000$ km…
In a recent investigation evidence was presented for a low-level sinusoidal oscillation superimposed on top of the Hubble flow. This oscillation was in V$_{CMB}$, in a sample of type Ia Supernovae sources with accurate distances, and it was…
Using a suite of N-body simulations in different Cold Dark Matter (CDM) scenarios, with cosmological constant (\LCDM) and without (OCDM, SCDM), we study the Hubble flow (\sigh) in Local Volumes (LV) around Local Group (LG) like objects…
Aims. We use accurate data on distances and radial velocities of galaxies around the Local Group, as well as around 14 other massive nearby groups, to estimate their radius of the zero-velocity surface, $R_0$, which separates any group…
Cosmic Flows is a program to determine galaxy distances for 30,000 galaxies with systematic errors below 2%, almost ten times the number currently known and a five-fold improvement in systematics. The resultant velocity field will provide…
We analyze the velocity field of peripheral members of the Local Group. The Hubble flow at distances from 400 to 1400~kpc, formed by 7 of 11 nearby galaxies, is characterized by an extremely small line-of-sight velocity dispersion of 15…
Recent cosmic microwave background (CMB) measurements over a large range of angular scales have become sensitive enough to provide interesting constraints on cosmological parameters within a restricted class of models. We use the CMB…
We present a new approach for quantifying the abundance of galaxy clusters and constraining cosmological parameters using dynamical measurements. In the standard method, galaxy line-of-sight (LOS) velocities, $v$, or velocity dispersions…
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,…
We present the first results from the Shellflow program, an all-sky Tully-Fisher (TF) peculiar velocity survey of 276 Sb-Sc galaxies with redshifts between 4500 and 7000 km/s. Shellflow was designed to minimize systematic errors between…
Recent local measurements of the Hubble constant made using supernovae have delivered a value that differs by $\sim$5$\sigma$ (statistical error) from predictions using the Cosmic Microwave Background (CMB), or using Baryon Acoustic…
The Hubble constant $H_0$ tension has emerged as the most serious crisis in modern cosmology, potentially indicating that the $\Lambda$CDM model may not describe our universe accurately. In this paper, we establish a new,…
Recently, we constructed the specific solution to the second-order cosmological perturbation theory, around any Friedmann-Lemaitre-Robertson-Walker (FLRW) background filled with dust matter and a positive cosmological constant. In this…
The {\it{Cosmological Boundary Flux Parameter}} is a novel proposal that attempts to explain the origin of the cosmological parameter $\Lambda$ purely by geometric nature. Then we implement this new approach to a flat FLRW universe along…
Despite the great observational success of the standard cosmological model some discrepancies in the inferred parameter constraints have manifested among a number of cosmological data sets. These include a tension between the expansion rate…
We establish a cosmological-model-independent method to determine the Hubble constant $H_0$ from the localized fast radio bursts (FRBs) and the Hubble parameter measurements from cosmic chronometers and obtain a first such determination…
In this work a satisfactory, simple theoretical prediction of the data corresponding to observationally (by fine tuning condition) estimated value of the cosmological constant is given. It is supposed (in conceptually analogy with…
We analyze how predictions of cosmological models depend on a choice of described observational data, restrictions on flatness, and how this choice can alleviate the $H_0$ tension. These effects are demonstrated in the $w$CDM model in…