What is the time dependence of the evolution of the observed ratio of dark energy to baryonic matter? The density-of-the-universe ratio varies from about (zero):1 at approximately 380,000 years after the big bang to about (15 to 18):1 at approximately today. [I infer the latter number from J. Beringer et al. (Particle Data Group), Phys. Rev. D86, 010001 (2012); http://pdg.lbl.gov/2012/reviews/rpp2012-rev-astrophysical-constants.pdf.] Have analyses estimated the evolution of the ratio, between the two times? Can someone point me to such results? Do any theories predict such results?
Hi
yes you can predict the time evolution of the ratio of dark energy and barionic energy. The dark energy if is explained wth a cosmological constant (the simplest one assumption) then dont have any time dependence. the barionic density decay over the time as a^-3 where a is scale factor of Universe. For the parameters that we can get from many different observations we can infer that around the present time, the dark energy and barionic energy are more or less of the same order. From thos we know that in the past the effects of dark energy arre very tiny, because the barionic density was orders of magtnitude bigger and the dark energy was the same value as today. In February of 2013, a new experiment called Planck can provide the answer if the dark energy is constant on time or it evolue with time passing. The best, Orlando
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