Related papers: Spatial and temporal tuning in void models for acc…
The degree of randomness in the cosmic microwave background (CMB) maps has been shown to be measurable and indicative of the hyperbolic effect of voids on the propagation of the photon beams. In terms of an introduced porosity parameter, we…
Departures of the energy spectrum of the cosmic microwave background (CMB) from a perfect blackbody probe a fundamental property of the universe -- its thermal history. Current upper limits, dating back some 25 years, limit such spectral…
We examine the decay vacuum model with a parameter $\epsilon$ that indicates the vacuum energy decay rate. By constraining this model with cosmic microwave background radiation, baryon acoustic oscillation, type Ia supernovae and 30 H(z)…
In this paper, we use a newly compiled sample of ultra-compact structure in radio quasars and strong gravitational lensing systems with quasars acting as background sources to constrain six spatially flat and non-flat cosmological models…
We review arguably the simplest solution for the Hubble tension -- the possibility that we live in a void. In this scenario, the local Hubble constant $H_0$ is higher than the global value, thus potentially explaining why $H_0$ measured…
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…
The mismatch between the locally measured expansion rate of the universe and the one inferred from the cosmic microwave background measurements by Planck in the context of the standard $\Lambda$CDM, known as the Hubble tension, has become…
We investigate the potential of using cosmic voids as a probe to constrain cosmological parameters through the gravitational lensing effect of the cosmic microwave background (CMB) and make predictions for the next generation surveys. By…
Cosmic voids have been shown to be an effective probe of cosmology, complementary to galaxy clusters. In this work, we present a simple theoretical framework for predicting of the size of the largest voids expected within a given redshift…
Cosmic voids are progressively emerging as a new viable cosmological probe. Their abundance and density profiles are sensitive to modifications of gravity, as well as to dark energy and neutrinos. The main goal of this work is to…
A spherical Lagrangian hydrodynamical code has been written to study the formation of cosmological structures in the early Universe. In this code we take into account the presence of collisionless non-baryonic cold dark matter (CDM), the…
Recent observations indicate a $4.9\sigma$ tension between the CMB and quasar dipoles. This tension challenges the cosmological principle. We propose that if we live in a gigaparsec scale void, the CMB and quasar dipolar tension can be…
We present a simple gravitational lens model to illustrate the ease of using the embedded lensing theory when studying cosmic voids. It confirms the previously used repulsive lensing models for deep voids. We start by estimating magnitude…
A wide range of large scale observations hint towards possible modifications on the standard cosmological model which is based on a homogeneous and isotropic universe with a small cosmological constant and matter. These observations, also…
Axions have emerged as compelling candidates for describing the dark sector of the Universe. In this work, we explore quintessence models inspired by axion-like potentials as a dynamical alternative to the cosmological constant. These…
Cosmic voids as typical under-density regions in the large scale Universe are known for their hyperbolic properties as an ability to deviate the photon beams. The under-density then is acting as the negative curvature in the hyperbolic…
Do current observational data confirm the assumptions of the cosmological principle, or is there statistical evidence for deviations from spatial homogeneity on large scales? To address these questions, we developed a flexible framework…
We present a novel method for simulation of the interior of large cosmic voids, suitable for study of the formation and evolution of objects lying within such regions. Following Birkhoff's theorem, void regions dynamically evolve as…
We present results from a numerical code implementing a new method to solve the master equations describing the evolution of linear perturbations in a spherically symmetric but inhomogeneous background. This method can be used to simulate…
A suggested solution to the dark energy problem is the void model, where accelerated expansion is replaced by Hubble-scale inhomogeneity. In these models, density perturbations grow on a radially inhomogeneous background. This large scale…