On the stackexchange I presented <https://physics.stackexchange.com/questions/257476/how-did-the-universe-shift-from-dark-matter-dominated-to-dark-energy-dominate/257542#257542> FLRW cosmology. The important equation is
(a'/a)^2 = 4πGρ/3 for a' = da/dt. The parameter a is a scale factor and the distance and velocity of a distant galaxy is v = xa' and d = xa. This equation also is the same as (a'/a)^2 = H^2 or that v = Hd. This is the Hubble relationship with the Hubble parameter H. The x in this is the standard ruler. This is determined by other means. The earliest such ruler was from Cepheid variables. Now for great distances type I supernovae are used. The value of the Hubble parameter is about 70m/s-Mpc. However as I indicated in my post on the big rip there is a growing chasm between this value as determined by the CMB and by galactic measurements. LC https://physics.stackexchange.com/questions/257476/how-did-the-universe-shift-from-dark-matter-dominated-to-dark-energy-dominate/257542#257542 On Friday, December 8, 2017 at 9:04:42 AM UTC-6, [email protected] wrote: > > How is it distinguished from red and possibly blue shifting due to > relative motion of distant galaxies? TIA, AG > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
