Related papers: Peculiar Velocity Anomaly from Forces Beyond Gravi…
It is known that the large-scale structure (LSS) mapped by a galaxy redshift survey is subject to distortions by galaxies' peculiar velocities. Besides the signatures generated in common N-point statistics, such as the anisotropy in the…
We present an analysis of the parallel peculiar velocity correlation function using data from the Cosmicflows-4 (CF4) survey. CF4 significantly extends the depth of the peculiar velocity measurements, mitigating the impact of observers on…
We give the first determination of the observed peculiar velocity distribution function for a representative sample of galaxies (within 50 Mpc (H=100) of the Local Group), which includes a wide range of clustering properties. We explore in…
We study the consequences of a homogeneous dark energy fluid having a non-vanishing velocity with respect to the matter and radiation large-scale rest frames. We consider homogeneous anisotropic cosmological models with four fluids…
To explain the currently observed accelerated expansion of the universe, a large number of different theoretical models are presently being discussed. In one way or another, all of these contain `new physics', though at different levels.…
The possibility that the present acceleration of the universe is driven by a kind of viscous fluid is exploited. At background level this model is similar to the generalized Chaplygin gas model (GCGM). But, at perturbative level, the…
The quasi-static solutions of the matter density perturbation in various dark energy models and modified gravity models have been investigated in numerous papers. However, the oscillating solutions in those models have not been investigated…
The dipole anomaly in the power spectrum of CMB may indicate that the Lorentz boost invarianc is violated at cosmic scale. We assume that the Lorentz symmetry is violated partly from the scale of galaxy. We employ the symmetry of very…
Growth of the structure in the Universe manifest as accretion flows of galaxies onto groups and clusters. Thus, the present day properties of groups and their member galaxies are influenced by the characteristics of this continuous infall…
We contrast features of simple varying speed of light (VSL) cosmologies with inflationary universe models. We present new features of VSL cosmologies and show that they face problems explaining the cosmological isotropy problem. We also…
The cosmological observations suggest that the presently accelerating universe should be filled by an exotic form of matter, violating the strong energy condition, of unknown nature and origin. We propose the viscous dark matter of a source…
There is now strong observational evidence that the expansion of the universe is accelerating. The standard explanation invokes an unknown "dark energy" component. But such scenarios are faced with serious theoretical problems, which has…
The energy scale of Dark Energy, $\sim 2 \times 10^{-3}$ eV, is a long way off compared to all known fundamental scales - except for the neutrino masses. If Dark Energy is dynamical and couples to neutrinos, this is no longer a coincidence.…
Galaxy clusters are the largest self-gravitational systems in the Universe. They are valuable probes of the structure growth of the Universe when we estimate their peculiar velocities with the kinematic Sunyaev-Zel'dovich (kSZ) effects. We…
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…
Using high-quality data on 149 galaxies within 10 megaparsecs (Mpc), I find no correlation between luminosity and peculiar velocity at all. There is no unequivocal sign on scales of 1-2 Mpc of the expected gravitational effect of the…
Maximum Likelihood estimation of the bulk flow from radial peculiar motions of galaxies, generally assumes a constant velocity field inside the survey volume. The assumption is inconsistent with the definition of the bulk flow as the…
Growing neutrino quintessence addresses the "why now" problem of dark energy by assuming that the neutrinos are coupled to the dark energy scalar field. The coupling mediates an attractive force between the neutrinos leading to the…
We introduce a new proposal for the onset of cosmic acceleration based on mass-varying neutrinos. When massive neutrinos become nonrelativistic, the $Z_2$ symmetry breaks, and the quintessence potential becomes positive from its initially…
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…