It is found that Gaia Data Release 3 binary stars selected with stringent requirements on
astrometric measurements and radial velocities naturally satisfy Newtonian dynamics …

(Abridged) Fundamental tensions between observations and dark-matter based
cosmological models have emerged. This updated review has two purposes: to explore new …

Galaxies in the early Universe appear to have grown too big too fast, assembling into
massive, monolithic objects more rapidly than anticipated in the hierarchical Lambda cold …

Compact massive relic galaxies are a class of galaxies that exhibit characteristics
suggesting they have remained largely unchanged since their initial formation, making them …

The Λ cold dark matter (ΛCDM) standard cosmological model is in severe tension with
several cosmological observations. Foremost is the Hubble tension, which exceeds 5σ …

Simulations of structure formation in the standard cold dark matter cosmological model
quantify the dark matter halos of galaxies. Taking into account dynamical friction between …

Context. Modified Newtonian dynamics (MOND) is a promising alternative to dark matter. To
further test the theory, there is a need for fluid-and particle-dynamics simulations. The force …

In the year 1924, a paper by Carl Wirtz appeared in 'Astronomische Nachrichten', entitled
'De Sitter's cosmology and the radial motion of spiral galaxies'. This paper and its author …

Galaxy number counts suggest that we are located within the Gpc-scale KBC void. The
Hubble tension might arise due to gravitationally driven outflow from this void, as explored in …

Ultra-diffuse galaxies (UDGs) in the Coma cluster have velocity dispersion profiles that are
in full agreement with the predictions of modified Newtonian dynamics (MOND) in isolation …