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 …

Horizon-scale images of black holes (BHs) and their shadows have opened an
unprecedented window onto tests of gravity and fundamental physics in the strong-field …

High energy collisions at the High-Luminosity Large Hadron Collider (LHC) produce a large
number of particles along the beam collision axis, outside of the acceptance of existing LHC …

We review applications of string theory to cosmology, from primordial times to the present-
day accelerated expansion. Starting with a brief overview of cosmology and string …

We review the current status of Early Dark Energy (EDE) models proposed to resolve the
“Hubble tension”, the discrepancy between “direct” measurements of the current expansion …

The difference from 4 to 6 σ in the Hubble constant (H 0) between the values observed with
the local (Cepheids and Supernovae Ia, SNe Ia) and the high-z probes (Cosmic Microwave …

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 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 parameter, H 0, is not an univocally defined quantity: It relates redshifts to
distances in the near Universe, but it is also a key parameter of the ΛCDM standard …