Theoretical spectroscopy of quasars within Karlsson's law
  The law introduced by Karlsson in spectroscopy of low-redshift quasars involves the Lyman spectrum of hydrogen atoms. Thus, it appears necessary to study the concepts introduced by a standard spectroscopy of quasars, studied here, with those deducted from $\Lambda$-CDM.A visible absorption of a sharp and saturated spectral line in a gas requires a long path without perturbations as collisions or cosmological redshift. Spectra of absorbed, saturated lines of quasars obeying Karlsson's law mainly result from interactions of natural, thermal light radiated by quasar with relatively cold, low presure atomic hydrogen. These lines are produced by three processes: a) A conventional absorption in a relatively cold gas produces a set of lines; b) These lines are multiplied by absorption after fundamental 3K or 4K redshifts, where K is Karlsson's constant: Spectra show that redshifts 3K (or 4K) exactly bring absorbed Lyman beta (or gamma) line on Lyman alpha: redshift almost disappears, and gas lines are intensely absorbed in the absence of alpha absorption; c) Redshifts occur in regions where light at alpha frequency is poorly absorbed due to permanent redshift, except when excitation of hydrogen to 2P level is sufficient for a superradiant flash emission at alpha frequency. This causes an intense absorption of high radiance rays from quasar, so the absorption of a line at current Lyman alpha frequency. Lightning and pumping produce relaxation oscillations that write many absorption lines. Redshifts by H atoms in 2P levels are due to parametric interactions composed of Impulsive Stimulated Raman Scatterings (ISRS): excited hydrogen atoms catalyze energy exchanges between observed ray and background cold thermal radiation, in agreement with thermodynamics. Description of Universe becomes much simpler, but less marvelous. 
Jacques Moret-Bailly
astro-ph.IM physics.optics