Nearby galaxies as pointers to a better theory of cosmic evolution

Abstract

The great advances in the network of cosmological tests show that the relativistic Big Bang theory is a good description of our expanding universe. But the properties of nearby galaxies that can be observed in greatest detail suggest a still better theory would more rapidly gather matter into galaxies and groups of galaxies. This happens in theoretical ideas now under discussion.In the standard cosmology [1] 4% of the mass of the universe is in the baryons of which stars and planets are made, 22% is nonbaryonic dark matter (DM), and the rest is Einstein's cosmological constant (or acts like it). Gravity has collected the dark matter in concentrations termed DM halos. In larger DM halos baryons were dense enough to have radiated away enough energy to collapse to galaxies and stars. The most massive halos, natural homes for the most luminous galaxies, preferentially form in regions of the highest local mass density.Less massive halos, natural homes for less luminous galaxies, appear in regions extending to lower local densities, in ridges of matter running between denser regions, forming a cosmic web [2] of filaments and sheets (as in Figs. 1 and 2 in [3]). This can be compared to the situation in our immediate extragalactic neighborhood illustrated in Figure 1. The Local Sheet at SGZ = 0 certainly looks like part of the cosmic web of the standard cosmology, but there are problems.Our selection of observations that seem to be pointing to an improved theory commences with the least crowded place in Figure 1, the Local Void, which contains far fewer galaxies than expected, while there is an unexpected presence of large galaxies on the outskirts of the Local Void. These problems would be eased if structure grew more rapidly than in the standard theory, more completely emptying the Local Void and piling up matter on its outskirts. In about half of the largest galaxies in Figure 1 the stars are largely confined

A Review on the Scalar Field/Bose-Einstein Condensate Dark Matter Model

“…The most massive halos, hosts for the brightest galaxies, are formed in regions with the highest local mass density. Less massive halos, hosts for the less bright galaxies, appear in regions with low local densities [94]. These situations appear to be the same as in our extragalactic neighborhood, but there are still problems.…”

“…These problems would be solved again if the structure grew faster than it does in the standard paradigm [94].…”

“…This problem would be solved if structure grew faster than in the standard theory, therefore filling the local void and giving rise to more matter in the surroundings ( [94]). …”

The galaxy population in cold and warm dark matter cosmologies

“…Full sky galaxy surveys in the local Universe have revealed that about a third of the Local Volume contains only 3 galaxies (Peebles 2001;Peebles & Nusser 2010). As noted above, these surveys are about 80 per cent complete to mB = 17.5 (Karachentsev et al 2014).…”

The Void Galaxy Survey

“…Largely unaffected by the complexities and processes modifying galaxies in high-density environments, the isolated void regions must hold important clues to the formation and evolution of galaxies. This makes the relation between void galaxies and their surroundings an important aspect of the interest in environmental influences on galaxy formation [33,13,16,24,26].…”