Abstract The standard Λ Cold Dark Matter (ΛCDM) cosmological model provides a good
description of a wide range of astrophysical and cosmological data. However, there are a …

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 simplest ΛCDM model provides a good fit to a large span of cosmological data but
harbors large areas of phenomenology and ignorance. With the improvement of the number …

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 …

Singularities in any physical theory are either remarkable indicators of the unknown
underlying fundamental theory, or indicate a change in the description of the physical reality …

Abstract This Primer examines Skilling's nested sampling algorithm for Bayesian inference
and, more broadly, multidimensional integration. The principles of nested sampling are …

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 …

Early dark energy (EDE) that behaves like a cosmological constant at early times (redshifts
z≳ 3000) and then dilutes away like radiation or faster at later times can solve the Hubble …

Abstract The recent Planck Legacy 2018 release has confirmed the presence of an
enhanced lensing amplitude in cosmic microwave background power spectra compared …

The strong discrepancy between local and early-time (inverse distance ladder) estimates of
the Hubble constant H 0 could be pointing towards new physics beyond the concordance Λ …