相关论文: Phase Transitions in the Early Universe
Existence and properties of the electroweak phase transition in the early universe depend strongly on the mass of the Higgs scalar M_H. There is presumably no true symmetry restoration at high temperature. Nevertheless, a first order phase…
When the universe was about 10 $\mu $seconds old, a first order cosmological quark - hadron phase transition occurred at a critical temperature of around 200 MeV. In this work, we study the quark-hadron phase transition in the context of…
The evolution of the Universe is the ultimate laboratory to study fundamental physics across energy scales that span about 25 orders of magnitude: from the grand unification scale through particle and nuclear physics scales down to the…
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…
At the early stage of the Universe-evolution there were no stars and no galaxies, but only a uniform hot plasma consisting of free electrons and free nuclei. The Universe temperature was determined by the Stefan-Boltzmann law of…
We investigate a new mechanism for the cosmological QCD phase transition: inhomogeneous nucleation. The primordial temperature fluctuations, measured to be $\delta T/T \sim 10^{-5}$, are larger than the tiny temperature interval, in which…
Based on hot big bang theory, the cosmological matter is conjectured to undergo QCD phase transition(s) to hadrons, when the universe was about $1-10 \mu$s old. In the present work, we study the quark-hadron phase transition, by taking into…
We study the dynamics of first-order phase transition in the early Universe when it was $10-50 \mu s$ old with quarks and gluons condensing into hadrons. We look at how the Universe evolved through the phase transition in small as well as…
The high-temperature limit of Standard Model generated by the contractions of gauge groups is discussed. Contraction parameters of gauge group $SU(2)$ of Electroweak Model and gauge group $SU(3)$ of Quantum Chromodynamics are taken…
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…
The study of cosmic phase transitions are of central interest in modern cosmology. In the standard model of cosmology the Universe begins in a very hot state, right after at the end of inflation via the process of reheating/preheating, and…
It is shown, for the first time , that surprisingly the electric charge loses all physical meaning above the electro-weak phase transition temperature. Implications of this discovery in the context of the early universe within the framework…
The three phase transitions - the GUT, the electro-weak and the quark-hadron, which the universe is assumed to have undergone produce very important physical effects if they are assumed to be of first order. It is also important that enough…
A QCD phase transition in the early universe could have left inhomogeneities in the baryon to photon ratio and in isospin that might have affected nucleosynthesis later on. At very high temperature QCD plasma can be described by…
The properties of elementary particles and their interactions at different stages of the evolution of the Universe, starting with the Planck energy $ 10 ^{19} $ GeV, are presented. We assume that the Standard Model gauge group becomes…
This dissertation aims to deepen the understanding of the primordial composition of the Universe in the temperature range 300 MeV>T>0.02 MeV. I exploit known properties of elementary particles and apply methods of kinetic theory and…
During the past two decades, cosmologists turned to particle physics in order to explore the physics of the very early Universe. The main link between the physics of the smallest and largest structures in the Universe is the idea of…
Phase transitions which occur at zero temperature when some non-thermal parameter like pressure, chemical composition or magnetic field is changed are called quantum phase transitions. They are caused by quantum fluctuations which are a…
We here argue that the "knee" of the cosmic ray energy distribution at $E_c \sim 1$ PeV represents a second order phase transition of cosmic proportions. The discontinuity of the heat capacity per cosmic ray particle is given by $\Delta…
We study non--equilibrium ensemble corrections to particle masses and the effective potential in the early universe, using a uniform momentum distribution as an example. The resulting thermalization temperature is computed assuming \sm…