A number of challenges to the standard Λ CDM model have been emerging during the past
few years as the accuracy of cosmological observations improves. In this review we discuss …

The Λ CDM model provides a good fit to most astronomical observations but harbors large
areas of phenomenology and ignorance. With the improvements in the precision and …

The Hubble tension has now grown to a level of significance which can no longer be
ignored and calls for a solution which, despite a huge number of attempts, has so far eluded …

The “S 8 tension” is a long-standing discrepancy between the cosmic microwave
background (CMB) and weak gravitational lensing determination of the amplitude of matter …

We study the effects of multiple transitions in the vacuum dark energy density on the H 0
tension problem. We consider a phenomenological model in which the vacuum energy …

In this study, we introduce a novel late-time effective dark energy model characterized by a
quadratic equation of state (EoS) and rigorously examine its observational constraints …

The presently open problem of the Hubble tension is shown to be removed in the context of
a modified theory of gravity with a non-minimal coupling between curvature and matter. By …

Despite the impressive success of the standard cosmological model, several anomalies defy
its triumph. Among them is the so-called lensing anomaly: The Planck satellite observes …

In this work, predictions of the Ginzburg–Landau theory of dark energy (GLT) for cosmic
microwave background (CMB) lensing are studied. We find that the time and scale …

In this work, we study the cosmological constant problem and Hubble tension in the void-
dominated cosmology scenario\cite {Yusofi: 2022hgg}. For this goal, we will first consider the …