SPIRAL GALAXY FORMATION BY CONDENSATION:
This section suggests that spiral galaxies 'condensed' during the epoch of Big Bang nucleosynthesis (BBN), promoted by endothermic temperature clamping in early baryon acoustic oscillations (BAO).
Direct Collapse Black Holes (DCBH):
"H2 molecule photo-dissociation enforces an isothermal collapse (Shang et al. 2010; Latif et al. 2013; Agarwal et al. 2013; Yue et al. 2014)*, finally leading to the formation of a DCBH of initial mass M• ' 10^4.5−5.5M Begelman et al. 2006; Volonteri et al. 2008; Ferrara et al. 2014), eventually growing up to 10^6−7M by accretion of the halo leftover gas."
(Pallottini et al. 2015)
These authors suggest that endothermic H2 molecule photo-dissociation promotes isothermal collapse to form intermediate-mass black holes which grow by gradual accretion to become supermassive black holes (SMBHs), whereas we suggest a much earlier collapse, during the epoch of BBN in which endothermic photodisintegration of helium promotes nearly-isothermal collapse to forming SMBHs directly, while capturing galaxy-mass halos of gravitationally-bound hydrogen and helium, designated 'proto-galaxies'.
Early baryon acoustic oscillation (BAO) condensation of proto-galaxies:
BAO at the epoch of recombination in ΛCDM imprinted its signature into the sea of photons which red shifted to become the cosmic microwave background (CMB) of today in the form of anisotropies; however, BAO occurred as early as the formation of charged particles and photons, prior to the epoch of Big Bang nucleosynthesis. During the epoch of nucleosynthesis (BBN), some 10 seconds to 20 minutes after the Big Bang, BAO compressions of the hydrogen-helium-neutron continuum are suggested to have condensed into gravitationally-bound proto-galaxies cored with supermassive DCBHs. Local BAO compressions raised the density and temperature above ambient, driving BBN backwards, in which photodisintegration of helium (helium fission) outpaced hydrogen fusion, endothermically clamping the temperature which allowed gravitational collapse to get the upper hand over thermal rebound. Where local compressions created event horizons, thermal rebound was impossible, and the first permanent structures of the universe came into being. And these supermassive DCBHs apparently held on to vast halos of gravitationally-bound matter even through the subsequent 'BBN-rebound' of the photodisintegration products, forming proto-galaxies with specific angular momentum.
Stars above 250 solar masses do not explode in supernovae, but instead collapse directly into black holes, bypassing exothermic helium fission to the still-hotter realm of endothermic photodisintegration, in which extremely energetic gamma rays are absorbed by atomic nuclei, causing them to emit a proton, neutron or alpha particle. Endothermic photodisintegration sufficiently clamps the temperature to cause runaway gravitational collapse to the point of surrounding the core with an event horizon, sequestering the matter in a black hole. (Photodisintegration is also responsible for p-process nucleosynthesis in supernovae.) Stars that exist in the vacuum of interstellar space require as little as 250 solar masses to achieve photodisintegration-mediated gravitational collapse, whereas early BAO compressions existed in the thick soup of the Big Bang continuum in which the super-super-high-density inward gravitational pressure of the local BAO compression was largely negated by the super-high-pressure of the BAO rarefaction beyond, requiring vastly-greater initial masse which created vastly-larger black holes. Thus the formation of SMBHs in the early universe are suggested to be an almost exact analogy to the death throes of stars above 250 solar masses today, with vastly-greater collapsing mass compensating for the vastly-greater background density of the early universe.
And the curvature of the BAO mediated condensation of proto-galaxies is suggested to be imprinted in the form of their specific angular momentum. So the typical specific angular momentum of spiral galaxies is evidence that the SMBHs retained galaxy-mass gravitationally-bound halos from the initial collapse. Much of the spherically distributed dark matter halos of spiral galaxies along with their associated dwarf galaxies (often aligned on a different axis than the spiral arms), however, may well have been gradually accreted after the initial condensation phase. So the SMBHs of the early universe were not naked, so to speak, but surrounded gravitationally-bound masses of hydrogen and helium, whose angular momentum may have protected the SMBHs from drawing in indefinitely-larger masses of net-zero-angular-momentum hydrogen and helium from the intergalactic continuum. The earliest proto-galaxies may have condensed the largest spiral proto-galaxies, with smaller proto-galaxies formed with ever diminishing ambient pressure from ever-increasing BAO curvature, such that later smaller condensed galaxies should also have lower specific angular momentum to the point that small irregular galaxies formed by condensation late in the epoch of BBN may simply have insufficient specific angular momentum to exhibit a spiral structure.
And thus, condensed proto-galaxies sequestered hydrogen and helium from the Big Bang continuum, substantially depleting the number of unbound baryons available to participate in BAO at the epoch of recombination when the BAO signature became frozen into the CMB in the form of BAO anisotropies. Thus if the ratio of baryonic matter sequestered into gravitationally-bound spiral-proto-galaxies at the epoch of recombination is sufficiently close to the ratio of dark matter to total matter in today's universe, then BAO anisotropies would not preclude baryonic dark matter, and the apparent big coincidence of the ratios may be far less stringent than it appears due to the 'missing baryon problem' of ΛCDM, wherein as much as half of the baryon density of the universe can not be found. Thus if a significant portion of the missing baryons are sequestered in dark matter globule clusters, then the apparent big coincidence may in reality be a small coincidence.
Pallottini, A.; Ferrara, A.; Pacucci, F.; Gallerani, S.; Salvadori, S.; Schneider, R.; Schaerer, D.; Sobral, D.; Matthee, J., 2015, The Brightest Lyα Emitter: Pop III or Black Hole?, MNRAS 000, 1–6 (2015).