Related papers: Energy density fluctuations in Early Universe
The evolution of a flat, isotropic and homogeneous universe is studied. The background geometry in the early phases of the universe is conjectured to be filled with causal bulk viscous cosmological fluid and dark energy. The energy density…
In first-order phase transitions in the early universe, the bubble wall is expected to be significantly slowed-down by its interaction with the surrounding plasma. We examine the behaviour of the phase of the Higgs field after two-bubble…
The scenario that some first-order phase transitions may have taken place in the early Universe offers us one of the most intriguing and fascinating questions in cosmology. Indeed, the role played by the latent "heat" or energy released in…
We study the evolution of a strong field plasma using a quantum Vlasov equation with a non-Markovian source term and a simple collision term, and calculate the time dependence of the energy- and number-density, and the temperature. The…
In this thesis the finite temperature transition between confined and deconfined matter is studied at zero and nonzero quark densities. The findings are relevant for the understanding of the evolution of the early Universe and contemporary…
A model of holographic dark energy with an interaction with matter fields has been investigated. Choosing the future event horizon as an IR cutoff, we have shown that the ratio of energy densities can vary with time. With the interaction…
We reexamine the recently proposed "little inflation" scenario that allows for a strong first order phase-transition of QCD at non-negligible baryon number in the early universe and its possible observable consequences. The scenario is…
After a review of CMBR correlations and recent observations, a study of possible CMBR observations of the QCD early universe phase transition is discussed. A model for the QCD bubble walls gives the surface tension found in lattice…
We determine the nature of the QCD transition using lattice calculations for physical quark masses. Susceptibilities are extrapolated to vanishing lattice spacing for three physical volumes, the smallest and largest of which differ by a…
Primordial chemistry began, at the recombination epoch, when the adiabatic expansion caused the temperature of the radiation to fall below 4000K. The chemistry of the early Universe involves the elements hydrogen, its isotope deuterium,…
In this work, the quark-hadron phase transition in a chameleon Brans-Dicke model of brane world cosmology within an effective model of QCD is investigated. Whereas, in the chameleon Brans-Dicke model of brane world cosmology, the Friedmann…
In the early universe, neutrinos decouple from equilibrium with the electromagnetic plasma at a temperature which is only slightly higher than the temperature where electrons and positrons annihilate. Therefore neutrinos to some extent…
We study the evolution of primordial magnetic fields in an expanding cosmic plasma. For this purpose we present a comprehensive theoretical model to consider the evolution of MHD turbulence that can be used over a wide range of physical…
Neutrino physics in the early Universe is key to our understanding of later cosmological stages, such as primordial nucleosynthesis (BBN) or the formation of large-scale structures. The coming decade promises new experimental results to…
We study the system of interacting axions and magnetic fields in the early universe after the quantum chromodynamics phase transition, when axions acquire masses. Both axions and magnetic fields are supposed to be spatially inhomogeneous.…
We revisit the phase structure and thermodynamics of QCD in the low temperature and high density region, where a strong, first-order phase transition is expected beyond the critical end point. By solving the quark gap equation in the…
In this paper it is suggested that inclusion of mutual gravitational interactions among the particles in the early dense universe can lead to a 'pre-big bang' scenario, with particle masses greater than the Planck mass implying an…
We study a class of early dark energy models which has substantial amount of dark energy in the early epoch of the universe. We examine the impact of the early dark energy fluctuations on the growth of structure and the CMB power spectrum…
The universe has evolved through several phases as its various constituents dominated its energy content. Candidate dark matter particles may have undergone freeze-out during any such phase. While the standard freeze-out scenarios have been…
Vacuum energy changes during cosmological phase transitions and becomes relatively important at epochs just before phase transitions. For a viable cosmology the vacuum energy just after a phase transition must be set by the critical…