ASTROPHYSICAL CHEMISTRY OF THE DARK UNIVERSE

We present a physico-chemical approach to determine the composition of the universe and elucidate the nature of Dark Energy and Dark Matter. It is based on a dynamical model that space consists of energy quanta which is an active participant in the evolution of the universe, along with matter and radiation. The universe evolved from an atomic size volume of spaceons at very high temperature and pressure near the Planck epoch. Upon expansion and cooling, phase transitions occurred resulting in the formation of fundamental particles, and matter. These nucleate and grow into stars, galaxies, and clusters with the aid of gravity. From the cooling curve of the universe we constructed a thermodynamic phase diagram of cosmic composition, from which we obtained a correlation between dark energy and the energy of space. Using the Friedmann equations, data from WMAP studies on the composition of the universe at 3.8 x 105 years (a=5.25 x 10-3) and at present (a=1), are well fitted by our model with an equation of state parameter, w= -0.7. The fit also showed the dominance of dark energy at 7.25 x 109 years ( a= 0.65), in good agreement with the beginning of the accelerated expansion of the universe at about 7 years, as determined by BOSS measurements. The expansion of space is attributed to Quintessence arising from a quantum space field. Dark Matter is identified as a plasma form of matter similar to that which existed during the photon epoch immediately prior to recombination. The thermodynamics of expansion of the universe was adiabatic with the rate decelerating during the first 7 billion years after the Big Bang. However, it became non-adiabatic and accelerating thereafter. Our Quantum Space Model suggests that an influx of energy from a source outside the universe maybe a possible cause of the accelerating expansion. If the expansion were to remain adiabatic, then thermodynamics requires that the pressure of space be negative in order for mass-energy to be conserved in the closed universe