Related papers: Testing the local supervoid solution to the Hubble…
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 KBC void is a local underdensity with the observed relative density contrast $\delta \equiv 1 - \rho/\rho_{0} = 0.46 \pm 0.06$ between 40 and 300 Mpc around the Local Group. If mass is conserved in the Universe, such a void could…
The inconsistency between the locally inferred Hubble constant and the value inferred from the cosmic microwave background assuming the $\Lambda$CDM cosmological model has persisted, turning into an important problem. An emergent underlying…
Galaxy number counts suggest that we are located within the Gpc-scale KBC void. The Hubble tension might arise due to gravitationally driven outflow from this void, as explored in detail by Haslbauer et al. We explore how the impact of the…
Nowadays, one of the well-known serious challenges in cosmology is the Hubble tension, namely the discrepancy between the Hubble constants from the local observation of Type Ia supernova (SNIa) and the high-$z$ observation of cosmic…
As tracers of the underlying mass distributions, the peculiar velocities of galaxies are valuable probes of the Universe, allowing us to measure the Hubble constant or to map the large-scale structure and its dynamics. The catalogs of…
We revisit our mapping of the `Local Hole', a large underdensity in the local galaxy redshift distribution that extends out to redshift, $z\approx0.05$ and a potential source of outflows that may perturb the global expansion rate and thus…
A potential solution to the Hubble tension is the hypothesis that the Milky Way is located near the center of a matter underdensity. We model this scenario through the Lema\^itre-Tolman-Bondi formalism with the inclusion of a cosmological…
There is substantial and growing observational evidence from the normalized luminosity density in the near-infrared that the local universe is under-dense on scales of several hundred Megaparsecs. We test whether our parameterization of the…
The increasing tension between the different local direct measurements of the Hubble expansion rate and that inferred from the Cosmic Microwave Background observation by $\Lambda$-Cold-Dark-Matter model could be a smoking gun of new…
We present an estimate of the bulk flow in a volume of radii $150-200h^{-1}$Mpc using the minimum variance (MV) method with data from the CosmicFlows-4 (CF4) catalog. The addition of new data in the CF4 has resulted in an increase in the…
We explore the possibility of using a gigaparsec-scale local void to reconcile the Hubble tension. Such a gigaparsec-scale void can be produced by multi-stream inflation where different parts of the observable universe follow different…
This work investigates the impact of cosmic flows and density perturbations on Hubble constant $H_0$ measurements using nonlinear phase-space reconstructions of the Local Universe (LU). In particular, we rely on 25 constrained N-body…
Using N-body simulations of flat, dark energy dominated cosmologies, we show that galaxies around simulated binary systems resembling the Local Group (LG) have low peculiar velocities, in good agreement with observational data. We have…
We use the largest sample to date of spectroscopic SN Ia distances and redshifts to look for evidence in the Hubble diagram of large scale outflows caused by local voids suggested to exist at z<0.15. Our sample combines data from the…
Zehavi et al. (1998) have suggested that the Hubble flow within 70/h Mpc may be accelerated by the existence of a void centered on the Local Group. Its underdensity would be ~20 %, which would result in a local Hubble distortion of about…
The Universe may feature large-scale inhomogeneities beyond the standard paradigm, implying that statistical homogeneity and isotropy may be reached only on much larger scales than the usually assumed $\sim$100 Mpc. This means that we are…
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…
We use updated data on distances and velocities of galaxies in the proximity of the Local Group (LG) in order to establish properties of the local Hubble flow. For 30 neighbouring galaxies with distances 0.7 < D_LG < 3.0 Mpc, the Local flow…
The current $>3\sigma$ tension between the Hubble constant $H_0$ measured from local distance indicators and from cosmic microwave background is one of the most highly debated issues in cosmology, as it possibly indicates new physics or…