scholarly journals THE BIG BANG AS A PHASE TRANSITION

2005 ◽  
Vol 20 (10) ◽  
pp. 2037-2045 ◽  
Author(s):  
TOMÁŠ LIKO ◽  
PAUL S. WESSON

We study a five-dimensional cosmological model, which suggests that the universe began as a discontinuity in a scalar (Higgs-type) field, or alternatively as a conventional four-dimensional phase transition.

Author(s):  
Francisco César de Sá Barreto ◽  
Luiz Paulo Ribeiro Vaz ◽  
Gabriel Armando Pellegatti Franco

The standard cosmological model suggests that after the “Big Bang”, 14 billion of years ago, the universe entered a period of expansion and cooling. In the first one millionth of a second appear quarks, glúons, electrons and neutrinos, followed by the appearance of protons and neutrons. In this paper, we describe the “cosmic battle” between gravitation and energy, responsible for the lighter chemical elements and the formation of the stars. We describe the thermodynamics of irreversible processes of systems which are far away from equilibrium, a route that is followed by the universe, seen as a living system.


KronoScope ◽  
2014 ◽  
Vol 14 (1) ◽  
pp. 71-89 ◽  
Author(s):  
Ettore Minguzzi

Abstract This paper proposes a cosmological model that uses a causality argument to solve the homogeneity and entropy problems of cosmology. In this model, a chronology violating region of spacetime causally precedes the remainder of the Universe, and a theorem establishes the existence of time functions precisely outside the chronology violating region. This model is shown to nicely reproduce Augustine of Hippo’s thought on time and the beginning of the Universe. In the model, the spacelike boundary representing the Big Bang is replaced by a null hypersurface at which the gravitational degrees of freedom are almost frozen while the matter and radiation content is highly homogeneous and thermalized.


Author(s):  
Abraham Loeb ◽  
Steven R. Furlanetto

This chapter considers the emergence of the complex chemical and radiative processes during the first stages of galaxy formation. It studies the appearance of the first stars, their feedback processes, and the resulting ionization structures that emerged during and shortly after the cosmic dawn. The formation of the first stars tens or hundreds of millions of years after the Big Bang had marked a crucial transition in the early Universe. Before this point, the Universe was elegantly described by a small number of parameters. But as soon as the first stars formed, more complex processes entered the scene. To illustrate this, the chapter provides a brief outline of the prevailing (though observationally untested) theory for this cosmological phase transition.


1994 ◽  
Vol 05 (02) ◽  
pp. 379-381
Author(s):  
K. FARAKOS ◽  
K. KAJANTIE ◽  
K. RUMMUKAINEN ◽  
M. SHAPOSHNIKOV

According to the electroweak baryogenesis scenario the matter-antimatter asymmetry of the Universe was created shortly after the Big Bang, during the electroweak phase transition. This process depends strongly on the detailed nature of the electroweak phase transition. For realistic Higgs particle masses, the standard perturbative analysis indicates that the transition is at most only weakly first order. We have studied the transition with non-perturbative lattice Monte Carlo simulations. We found large non-perturbative effects; in particular, the phase transition is a strongly first order one, at least up to Higgs mass of about 85 GeV. This makes electroweak baryogenesis a viable scenario with a Higgs mass not exceeding 85 GeV.


Universe ◽  
2020 ◽  
Vol 6 (6) ◽  
pp. 87
Author(s):  
Jaume Haro Cases ◽  
Llibert Aresté Saló

One of the most important issues in an inflationary theory as standard or quintessential inflation is the mechanism to reheat the universe after the end of the inflationary period in order to match with the Hot Big Bang universe. In quintessential inflation two mechanisms are frequently used, namely the reheating via gravitational particle production which is, as we will see, very efficient when the phase transition from the end of inflation to a kinetic regime (all the energy of the inflaton field is kinetic) is very abrupt, and the so-called instant preheating which is used for a very smooth phase transition because in that case the gravitational particle production is very inefficient. In the present work, a detailed study of these mechanisms is done, obtaining bounds for the reheating temperature and the range of the parameters involved in each reheating mechanism in order that the Gravitational Waves (GWs) produced at the beginning of kination do not disturb the Big Bang Nucleosynthesis (BBN) success.


2015 ◽  
Vol 24 (12) ◽  
pp. 1544029
Author(s):  
N. Afshordi ◽  
R. B. Mann ◽  
R. Pourhasan

We present a cosmological model in which the Universe emerges out of the collapse of a five-dimensional (5D) star as a spherical three-brane. The initial singularity of the big bang becomes hidden behind a causal horizon. Near scale-invariant primordial curvature perturbations can be induced on the brane via a thermal atmosphere that is in equilibrium with the brane, circumventing the need for a separate inflationary process and providing an important test of the model.


2018 ◽  
Vol 96 (9) ◽  
pp. 992-998
Author(s):  
G.P. Singh ◽  
N. Hulke ◽  
Ashutosh Singh

In this paper, we consider the framework of nonlinear electrodynamics in locally rotationally symmetric (LRS) Bianchi-I universe model composed of magnetic fluid. It has been shown that an accelerated universe expansion takes place if the nonlinear electromagnetic field is a source of gravitational field. In this model, after the big bang, the universe undergoes inflation and the accelerated expansion, dissipates the initial anisotropy of the curvature part without using a selected initial condition. Further validity of generalised second law of thermodynamics in the cosmological model enclosed by apparent horizon is investigated. We also discuss the classical stability of the cosmological model and observational viability of the model.


Author(s):  
Mohamed Abdalla Bakry ◽  
Ali Eid ◽  
A. Alkaoud

In this article, we assume that the beginning of the universe was before the Big Bang. In the beginning, all matter in the universe was combined in an infinitesimal spherical shape. This sphere was compressed to an incomprehensible value for a period, and then exploded and expanded time and space. We are referring to the negative time before the Big Bang. The evolution of the universe before the Big Bang, passing through the moment of the explosion to the end of the universe at the Big Rip, has been studied. In this article, we try to answer the questions; did the universe exist before the Big Bang? What is the origin of the universe and how did it arise? What are the stages of the evolution of the universe until the moment of the Big Rip? What is the length of time for the stages of this development?


2006 ◽  
Vol 190 ◽  
pp. 15-15
Author(s):  
D CASTELVECCHI
Keyword(s):  
Big Bang ◽  

Author(s):  
Jan Zalasiewicz

This is the story of a single pebble. It is just a normal pebble, as you might pick up on holiday - on a beach in Wales, say. Its history, though, carries us into abyssal depths of time, and across the farthest reaches of space. This is a narrative of the Earth's long and dramatic history, as gleaned from a single pebble. It begins as the pebble-particles form amid unimaginable violence in distal realms of the Universe, in the Big Bang and in supernova explosions and continues amid the construction of the Solar System. Jan Zalasiewicz shows the almost incredible complexity present in such a small and apparently mundane object. Many events in the Earth's ancient past can be deciphered from a pebble: volcanic eruptions; the lives and deaths of extinct animals and plants; the alien nature of long-vanished oceans; and transformations deep underground, including the creations of fool's gold and of oil. Zalasiewicz demonstrates how geologists reach deep into the Earth's past by forensic analysis of even the tiniest amounts of mineral matter. Many stories are crammed into each and every pebble around us. It may be small, and ordinary, this pebble - but it is also an eloquent part of our Earth's extraordinary, never-ending story.


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