Related papers: Evolution of primordial H2 for different cosmologi…
Several processes in the early universe might lead to the formation of primordial black holes with different masses. These black holes would interact with the cosmic plasma through accretion and emission processes. Such interactions might…
Primordial black holes with a narrow mass range are regarded as a nonrelativistic fluid component with an equation of state for dust. The impact of the black hole evaporation on the dynamics of the early universe is studied by resorting to…
We examine the processes of formation and destruction of LiH molecules in the primordial gas at temperatures T \leq 5000 K in the framework of standard Friedmann cosmological models and we compute the optical depth of the Universe due to…
After the recombination of Hydrogen, primordial molecules such as H_2, $HD$ can be formed.The formation of structures in the post-recombination gaseous medium is commonly explained by primordial density fluctuations. In a self-gravitating…
One of the main challenges in cosmology is to quantify how small density fluctuations at the recombination epoch z around 1000 evolved into the galaxies and the large-scale structure we observe in the universe today. This thesis discusses…
We present a general set of calculations decribing the chemical evolution of young massive galaxies and predict the evolution of the CO, O2, and dust abundances as a function of age and metallicity.
At low temperatures, the main coolant in primordial gas is molecular hydrogen, H2. Recent work has shown that primordial gas that is not collapsing gravitationally but is cooling from an initially ionized state forms hydrogen deuteride, HD,…
During its early evolution, the hot, dense Universe provided a laboratory for probing fundamental physics at high energies. By studying the relics from those early epochs, such as the light elements synthesized during primordial…
Primordial molecules were formed during the Dark Ages, i.e. the time between recombination and reionization in the early Universe. The purpose of this article is to analyze the formation of primordial molecules based on heavy elements…
The chemistry of the early Universe is a fascinating field of study. Even in the absence of any elements heavier than lithium, a surprising degree of chemical complexity proves to be possible, giving the topic considerable interest in its…
The origin of life and the origin of the universe are among the most important problems of science and they might be inextricably linked. Hydro-gravitational-dynamics (HGD) cosmology predicts hydrogen-helium gas planets in clumps as the…
Non-thermal photons deriving from radiative transitions among the internal ladder of atoms and molecules are an important source of photons in addition to thermal and stellar sources in many astrophysical environments. In the present work…
Galactic destruction of primordial deuterium is inevitably linked through star formation to the chemical evolution of the Galaxy. The relatively high present gas content and low metallicity suggest only modest D-destruction. In concert with…
Hydrogen recombination in the early Universe in the presence of a magnetic field is studied. An equation for the temperature of recombination in the presence of a magnetic field is derived. Limiting cases of weak and strong fields are…
Assuming that the background geometry is filled with free gas consisting of matter and radiation and no phase transitions being occurred in the early Universe, we discuss the thermodynamics of this {\it closed} system using classical…
Mirror matter is a promising self-collisional dark matter candidate. Here we study the evolution of thermodynamical quantities in the early Universe for temperatures below ~100 MeV in presence of a hidden mirror sector with unbroken parity…
The first eight elements of the periodic table are discussed: H, He, Li, Be, B, C, N, and O. They are referred to as key elements, given their important role in stellar evolution. It is noteworthy that all of them were initially synthesized…
A possibility that the universe may be strongly inhomogeneous chemically, while very smooth energetically, is considered. A possible mechanism which could lead to such a picture is a large and inhomogeneous lepton asymmetry. The model may…
The interplay between chemistry and thermodynamics determines the final outcome of the process of gravitational collapse and sets the conditions for the formation of the first cosmological objects, including primordial supermassive black…
The basic processes of the formation of the first stars in the primordial Universe are outlined and the implications for cosmological structure formation discussed. By employing theoretical and numerical models of cosmic structure evolution…