Speaker
Description
The explanation of a puzzling observation by Bowman et al 2018 (Nature, 555, 67) of the redshifted 21 cm spectral line from the early Universe, where it was found that the absorption in this line was about 2 to 3 times stronger than predicted by the standard cosmology and thus the primordial hydrogen gas was significantly cooler than predicted by the standard cosmology, required as the cooling agent, some kind of baryonic DM [Barcana, 2018 (Nature, 555, 71); McGaugh, 2018 (Res. Not. Amer. Astron. Soc., 2, 37)]. Then in paper [Oks, 2020 (Res. Astron. Astrophys. 20, 109)] there was given both qualitative and quantitative explanation of the puzzling observation by Bowman et al (2018) based on the specific DM in the form of the second flavor of hydrogen atoms (SFHA), corresponding to the 2nd solution of the Dirac equation for hydrogen atoms. In distinction to exotic hypothetical particles previously suggested as the explanation (the particles never discovered experimentally), the existence of the SFHA is evidenced by 3 different types of atomic experiments – plus it completely resolved the long-standing puzzle of the neutron lifetime. In the latter, the central point was that the two-body decay of neutrons produces – with the overwhelming probability – the SFHA rather than the usual hydrogen atoms. More details can be found, e.g., in my reviews on DM published in New Astronomy Reviews in 2021 (93, 101632) and in 2023 (96, 101673), and in my paper in Nuclear Phys. B 2025 (1014, 116879). The primary property of the SFHA is that, since they have only the S-states, then according to the selection rules of quantum mechanics they cannot emit or absorb the electromagnetic radiation: they remain dark. As the relation of these results to the structure formation in the universe, I provide the chronology of the cosmological formation of the surplus of the SFHA (compared to the usual hydrogen atoms) from the Recombination Epoch through the Structure Formation Epoch, including the production of the SFHA by some neutron stars. Therefore, the halos of modern galaxies contain more of the SFHA than the usual H-atoms. In addition, there is evidence from atomic experiments of the existence of the Second Flavor of He+ Ions (SFHeI). They are also dark due to the selection rules of quantum mechanics. There occurred the cosmological formation of the surplus of the SFHeI (compared to the usual He+) similarly to the surplus of the SFHA. Therefore, the halos of modern galaxies contain also more of the SFHeI than the usual He+. From atomic experiments follows that the most probable value of ratio (SFHA + SFHeI)/(usual H + usual He+) is 1.8. From astrophysical observations by de Graaff et al (2019, A&A, 624, A48) and by Penton et al (2004 ApJ Suppl. Ser. 152, 29) follows that the most probable value of the ratio (baryonic DM)/(luminous baryons) is 2.1. The comparison of these two ratios shows that the combination of the SFHA with the SFHeI most probably constitutes about 90% of all baryonic DM in the current epoch. It is important to emphasize that the discovery of the SFHA and the SFHeI was based on the standard Dirac equation of quantum mechanics without going beyond the Standard Model and without any change of physical laws – in distinction to the overwhelming majority of hypotheses on DM. Finally, I will discuss/motivate some relevant future laboratory experiments and astrophysical observations.