相关论文: Time Since the Beginning

Cosmological inflation, if it occurred, radically alters the picture of the `big bang', which would merely point to reheating at the end of inflation. Moreover, this reheating may be only local, so that inflation continues elsewhere and…

The cosmic inflation hypothesis, its relation to fundamental theory on the beginning of the universe, and the light that both shed on how the various elements and their relative amounts came into existence. The fundamental factors…

Modern physics has unlocked a number of mysteries regarding the early Universe, such as the baryogenesis, the unification of the strong and electroweak forces and the nucleosynthesis. However, understanding the very early Universe, close to…

How did it all begin? Although this question has undoubtedly lingered for as long as humans have walked the Earth, the answer still eludes us. Yet since my grandparents were born, scientists have been able to refine this question to a…

I study a model which describes the birth of the universe using a global topological phase transition with a complex manifold where the time, $\tau$, is considered as a complex variable. Before the big bang $\tau$ is a purely imaginary…

We propose a cosmological lingering phase for the initial state prior to inflation which would help address the singularity problem of inflation. The universe begins with a constant (Hagedorn) temperature and then transitions into an…

There is very strong circumstantial evidence that there was an inflationary epoch very early in the history of the universe. In this lecture I will describe how we might be able to piece together some understanding of the dynamics during…

An introductory account is given of the inflationary cosmology, which postulates a period of accelerated expansion during the Universe's earliest stages. The historical motivation is briefly outlined, and the modelling of the inflationary…

If our universe underwent inflation, its entropy during the inflationary phase was substantially lower than it is today. Because a low-entropy state is less likely to be chosen randomly than a high-entropy one, inflation is unlikely to…

The hypothesis that the Universe underwent a period of exponential expansion at very early times has become the most popular theory of the early Universe. Not only does it solve some of the problems of standard big bang cosmology, but it…

In a unified picture both inflation and present dynamical dark energy arise from the same scalar field. The history of the Universe describes a crossover from a scale invariant "past fixed point" where all particles are massless, to a…

An introductory account is given of the modern understanding of the physics of the early Universe. Particular emphasis is placed on the paradigm of cosmological inflation, which postulates a period of accelerated expansion during the…

We study the origin of the universe (or pre-inflation) by suggesting that the primordial space-time in the universe suffered a global topological phase transition, from a 4D Euclidean manifold to an asymptotic 4D hyperbolic one. We…

We review the current standard model for the evolution of the Universe from an early inflationary epoch to the complex hierarchy of structure seen today. We summarize and provide key references for the following topics: observations of the…

Inflation is a bold and expansive extension of the Standard Cosmology. It holds the promise to extend our understanding of the Universe to within 10^{-32}sec of the big bang and answer most of the pressing questions in cosmology. Its…

In the inflationary scenario all the matter constituting the universe was created from the process of reheating after inflation. Recent development of the theory of reheating is briefly reviewed. The list of topics includes elementary…

Inflation has been the leading early universe scenario for two decades, and has become an accepted element of the successful `cosmic concordance' model. However, there are many puzzling features of the resulting theory. It requires both…

Cosmological phase transitions are thought to have taken place at the early Universe imprinting their properties on the observable Universe. There is strong evidence that, through the dynamics of a scalar field that lead a second order…

We discuss cosmological models for an eternal universe. Physical observables show no singularity from the infinite past to the infinite future. While the universe is evolving, there is no beginning and no end - the universe exists forever.…

The basic workings of inflationary models are summarized, along with the arguments that strongly suggest that our universe is the product of inflation. It is argued that essentially all inflationary models lead to (future-)eternal…