相关论文: Hubble Parameter in Void Universe

Redshift drift is the phenomenon whereby the observed redshift between an emitter and observer comoving with the Hubble flow in an expanding FLRW universe will slowly evolve -- on a timescale comparable to the Hubble time. There are…

Voids are dominant features of the cosmic web. We revisit the cosmological information content of voids and connect void properties with the parameters of the background universe. We combine analytical results with a suite of large n-body…

We examine the cosmological implications of measurements of the void-galaxy cross-correlation at redshift $z=0.57$ combined with baryon acoustic oscillation (BAO) data at $0.1<z<2.4$. We find direct evidence of the late-time acceleration…

We compile a list of 28 independent measurements of the Hubble parameter between redshifts 0.07 < z < 2.3 and use this to place constraints on model parameters of constant and time-evolving dark energy cosmologies. These H(z) measurements…

The cosmological principle asserts that the Universe looks spatially homogeneous and isotropic on sufficiently large scales. Given the fundamental implications of the cosmological principle, it is important to empirically test its validity…

The observational behavior of spherically symmetric inhomogeneous cosmological models is studied, which consist of inner and outer homogeneous regions connected by a shell or an intermediate self-similar region. It is assumed that the…

According to the cosmological principle, the Universe should appear isotropic, without any preferred directions, to an observer whom we may consider to be fixed in the co-moving co-ordinate system of the expanding Universe. Such an observer…

For a flat $\Lambda$CDM universe, the dipole of the luminosity distance can be utilized to measure the Hubble parameter. It is here shown that this is not the case in more general settings where curvature and cosmic backreaction is…

We assess the dominant low-redshift anisotropic signatures in the distance-redshift relation and redshift drift signals. We adopt general-relativistic irrotational dust models allowing for gravitational radiation -- the `quiet universe…

We state a condition for an observer to be comoving with another observer in general relativity, based on the concept of lightlike simultaneity. Taking into account this condition, we study relative velocities, Doppler effect and light…

The Hubble constant is one of the most important parameters in cosmology. Discrepancies in values of the Hubble constant estimated from various measurements, the so-called Hubble tension, are a serious problem. In this paper, we study the…

The cosmic microwave background temperature is a cornerstone astrophysical observable. Its present value is tightly constrained, but its redshift dependence, which can now be determined until redshift $z\sim6.34$, is also an important probe…

Recent attempts at measuring the variation of $c$ using an assortment of standard candles and the redshift-dependent Hubble expansion rate inferred from the currently available catalog of cosmic chronometers have tended to show that the…

We have previously shown that spherically symmetric, inhomogeneous universe models can explain both the supernova data and the location of the first peak in the CMB spectrum without resorting to dark energy. In this work, we investigate…

The discrepancy between the amplitudes of matter fluctuations inferred from Sunyaev-Zel'dovich (SZ) cluster number counts, the primary temperature, and the polarization anisotropies of the cosmic microwave background (CMB) measured by the…

Recent analyses of large-scale structure and redshift surveys have reported significant dipolar anisotropies in the local Universe that are not straightforwardly attributable to a global kinematic boost. When interpreted within standard…

The dependence of Hubble parameter on redshift can be determined directly from the dipole of luminosity distance to Supernovae Ia. We investigate the possibility of using the data on dipole of the luminosity distance obtained from the…

Yes. In a perturbed Friedmann model, the difference of the Hubble constants measured in two rest-frames is independent of the source peculiar velocity and depends only on the relative velocity of the observers, to lowest order in velocity.…

In an isotropic and homogeneous Hubble expansion, all transverse motion is peculiar. Like the radial peculiar velocities of galaxies, transverse peculiar velocities are a means to trace the density of matter that does not rely on light…

For 100 years since galaxies were found to be flying apart from each other, astronomers have been trying to determine how fast. The expansion, characterized by the Hubble constant, H0, is confused locally by peculiar velocities caused by…