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 …

Old-aged stellar distance indicators are present in all Galactic structures (halo, bulge, disk)
and in galaxies of all Hubble types and, thus, are immensely powerful tools for …

Abstract The Λ Cold Dark Matter model (ΛCDM) represents the current standard model in
cosmology. Within this, there is a tension between the value of the Hubble constant, H 0 …

Context. Milky Way dwarf satellites are unique objects that encode the early structure
formation and therefore represent a window into the high redshift Universe. So far, their …

Quasars have been proposed as a new class of standard candles analogous to supernovae,
since their large redshift range and high luminosities make them excellent candidates. The …

Abstract As Setti and Woltjer noted back in 1973, one can use quasars to construct the
Hubble diagram; however, the actual application of the idea was not that straightforward. It …

We review the properties of the established Scaling Relations (SRs) of galaxies and active
galactic nuclei (AGN), focusing on their origin and expected evolution back in time, providing …

Context. When can an active galactic nucleus (AGN) be considered radio loud (RL)?
Following the established view of the AGNs inner workings, an AGN is RL if associated with …

We study the Bianchi-I cosmological model motivated by signals of statistical isotropy
violation seen in cosmic microwave background (CMB) observations and others. To that …

Distance measurements for extragalactic objects are a fundamental problem in astronomy,
and cosmology,. In the era of precision cosmology, we urgently need better measurements …