相关论文: Generating Intrinsic Dipole Anisotropy in the Larg…
We present an in depth discussion of the production of gravitational waves from an inflationary phase that could have occurred in the early universe, giving derivations for the resulting spectrum and energy density. We also consider the…
We constrain several models of the early Universe that predict a statistical anisotropy of the cosmic microwave background (CMB) sky. We make use of WMAP9 maps deconvolved with beam asymmetries. As compared to previous releases of WMAP…
A spherical cosmological model with a local void on scales of $\sim 200$ Mpc and with an inhomogeneous Hubble constant was proposed in recent two papers. This model explains consistently the observed properties of the cosmic bulk flow, the…
We employ Maximum Likelihood Estimators to examine the Pantheon+ catalogue of Type Ia supernovae for large scale anisotropies in the expansion rate of the Universe. The analyses are carried out in the heliocentric frame, the CMB frame, as…
Exact cosmological solutions are obtained for a five dimensional inhomogeneous fluid distribution along with a Brans-Dicke type of scalar field. The set includes varied forms of matter field including $\rho+p=0$, where p is the 3D isotropic…
We use observational data on the large scale structure (LSS) of the Universe measured over a wide range of scales from sub-galactic up to horizon scale and on the cosmic microwave background anisotropies to determine cosmological parameters…
Using two dimensional simulations, we study the formation of structures with a high-density contrast by magnetohydrodynamic waves in regions in which the ratio of thermal to magnetic pressure is small. The initial state is a uniform…
Gravitational collapse in cosmological context produces an intricate cosmic web of voids, walls, filaments and nodes. The anisotropic nature of collisionless collapse leads to the emergence of an anisotropic velocity dispersion, or stress,…
We derive a general expression for the probability of observing deviations from statistical isotropy in the cosmic microwave background (CMB) if the primordial fluctuations are non-Gaussian and extend to superhorizon scales. The primary…
The cosmological principle, as the cornerstone of the standard cosmological model, requires that the Universe be homogeneous and isotropic on large scales. As a fundamental assumption, it is constantly subjected to testing via various…
Search for the statistical anisotropy in the CMB data is a powerful tool for constraining models of the early Universe. In this paper we focus on the recently proposed cosmological scenario with conformal rolling. We consider two…
The spatial-dependent-propagation (SDP) model with a nearby source works well to reproduce the coevolving features of both cosmic-ray (CR)-nuclei spectra and anisotropy. However, it is well known that the Sun is actually deviating from the…
We present the first joint analysis of catalogs of radio galaxies and quasars to determine if their sky distribution is consistent with the standard $\Lambda$CDM model of cosmology. This model is based on the cosmological principle, which…
In strong gravitational lensing, the multiple images we see correspond to light rays that leave the source in slightly different directions. If the source emission is anisotropic, the images may differ from conventional lensing predictions…
Astronomical observations suggest that the Universe may be anisotropic on the largest scales. In order to model this situation, we develop a new approach to cosmology that allows for large-scale anisotropy to emerge from the growth of…
In the standard diffusive picture for transport of cosmic rays (CRs), a gradient in the CR density induces a typically small, dipolar anisotropy in their arrival directions. This has been widely advertised as a tool for finding nearby…
The cosmic dipole anomaly, currently detected at a significance exceeding 5$\sigma$ in several independent survey poses a significant challenge to the standard model of cosmology. The Ellis & Baldwin formula provides a theoretical link…
The motion of an observer in the rest frame of the cosmic 21-cm background induces an anisotropy in the observed background, even when the background is isotropic. The induced anisotropy includes a dipole and a quadrupole, in the order…
Gravitational redshift imprints a slight asymmetry in the observed clustering of galaxies, producing odd multipoles (e.g.\ the dipole) in the cross-correlation function. But there are other sources of asymmetry which must also be considered…
We characterize the peculiar velocity field of the local large-scale structure reconstructed from the $2M++$ survey, by treating it as a fluid, extracting the divergence via different approximations over a range pf averaged scales. This…