INFLATION IN COSMOLOGY

1999

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 epoch explained. The most important aspect of inflation is that it provides a possible model for the origin of structure in the Universe, and key results are reviewed, along with a discussion of the current observational situation and outlook.

Classical and Quantum Gravity, 2002

This article gives a brief overview of some of the theory behind the inflationary cosmology, and discusses prospects for constraining inflation using observations. Particular care is given to the question of falsifiability of inflation or of subsets of inflationary models. ‡

Astrophysics and Space Science Proceedings, 2008

We present a brief review of Cosmological Inflation from the personal perspective of the author who almost 30 years ago proposed a way of resolving the problem of Cosmological Horizon by employing certain notions and developments from the field of High Energy Physics. Along with a brief introduction of the Horizon and Flatness problems of standard cosmology, this lecture concentrates on personal reminiscing of the notions and ideas that prevailed and influenced the author's thinking at the time. The lecture then touches upon some more recent developments related to the subject and concludes with some personal views concerning the direction that the cosmology field has taken in the past couple of decades and certain speculations some notions that may indicate future directions of research.

International Journal of Current Research and Academic Review, 2017

Article Info The Standard Big Bang Cosmology gives the most accepted concept about the beginning and evolution of the Universe. However, it has problems: the flatness problem, the horizon problem and the monopole problem. The predictions of the Standard Big Bang Cosmology do not match the observations of modern cosmologists. Nonetheless, the admirers of the Standard Big Bang Cosmology continued to find out ways for solving those problems and such attempts lead to our knowledge of Inflationary Cosmology. The theory of inflation, which was first proposed by Alan Guth in 1981, soon became a "need" of modern cosmology and various modified models of inflationary Universe were proposed. In this paper, the author gives a brief insight of the Standard Big Bang Cosmology, introduces inflationary cosmology with its brief background, reviews some concepts associated with cosmic inflation, explains how inflation can be classified into various types, describes few of the popular types in brief and explains how the cosmological problems are solved by cosmic inflation. Moreover, few insightful examples have been given to easily explain the fundamental concepts so that even a junior researcher can get thorough idea about the field by escaping the equations and simply going through the text selectively.

Revista Mexicana de Física E, 2020

The main aim of this paper is to provide a qualitative introduction to the cosmological inflation theory and its relationship with current cosmological observations. The inflationary model solves many of the fundamental problemsthat challenge the Standard Big Bang cosmology such as the Flatness, Horizon and the magnetic Monopole problems. Additionally it provides an explanation for the initial conditions observed throughout the Large-Scale Structure of the Universe, such as galaxies. In this review we describe general solutions to the problems in the Big Bang cosmology carry out by a single scalar eld. Then, with the use of current surveys, we show the constraints imposed on the inflationary parameters (ns; r) which allow us to make the connection between theoretical and observational cosmology. In this way, with the latest results, it is possible to select or at least to constrain the right inflationary model, parameterized by a single scalar eld potential V (\phi).

Annals of the New York Academy of Sciences, 1984

For the reader who would like a more detailed review of this subject, let me point out that Reference 9 contains reviews by both A. D. Linde and myself. 'For a general background in cosmology, see Reference 25. At a less technical level, see References 26 and 27.

1990

In this project, we study the theory of cosmological inflation and its cosmological implications. Firstly, we present basic elements of the ΛCDM cosmological model as well as the shortcomings of the Big Bang theory which motivated inflationary scenarios in the primordial universe. Then,we adduce the standard single-field theory of inflation and describe the slow-roll conditions. Next, we present the theory of cosmological perturbations related to the inflaton field by analysing theories with massive or massless scalar fields in de Sitter or quasi de Sitter primordial universes. Consequently, we feature the scalar metric fluctuations coupled with the inflaton ones. In addition,we deduce the power spectrum of the curvature perturbations which is directly related to the fluctuations of the gravitational potential. Finally, we establish the relations between the curvature fluctuations and the matter density and temperature fluctuations which can be tested through observation.

Gravitation & Cosmology - GRAVIT COSMOL, 2005

We propose a revision of the most important results from the slow-roll approximation using an exact inflationary approach. The most important quantities which may be derived theoretically from slow-roll inflation and may then be compared with observational data, such as the curvature perturbation; the spectral index n(k ), a nd the derivative of the spectral index n with respect to ln k , are presented in an explicit form. We study these quantities in the case when a scalar field has a logarithmic evolution with time and for power-law inflation. tONAQ KOSMOLOGIESKAQ MODELX I SPECIFIKACIQ INFLQCIONNOGO SCENARIQ s.w. ˜ERWON, m. nOWELLO, r. tRIJE