Cosmological Constants


Book Description




The Constants of Nature


Book Description

Reality as we know it is bound by a set of constants—numbers and values that dictate the strengths of forces like gravity, the speed of light, and the masses of elementary particles. In The Constants of Nature, Cambridge Professor and bestselling author John D.Barrow takes us on an exploration of these governing principles. Drawing on physicists such as Einstein and Planck, Barrow illustrates with stunning clarity our dependence on the steadfastness of these principles. But he also suggests that the basic forces may have been radically different during the universe’s infancy, and suggests that they may continue a deeply hidden evolution. Perhaps most tantalizingly, Barrow theorizes about the realities that might one day be found in a universe with different parameters than our own.




Introduction to General Relativity and the Cosmological Constant Problem


Book Description

This book is an introductory text in General Relativity, while also focusing some solutions to the cosmological constant problem, which consists in an amazing 100 orders of magnitude discrepancy between the value of this constant in the present Universe, and its estimated value in the very early epoch. The author suggests that the constant is in fact, a time-varying function of the age of the Universe. The book offers a wealth of cosmological models, treats up to date findings, like the verification of the Lense-Thirring effect in the year 2004, and the recently published research by Cooperstock and Tieu (2005) suggesting that "dark" matter is not a necessary concept in order to explain the rotational velocities of stars around galaxies' nuclei. This is a mathematical cosmology textbook that may lead undergraduates, and graduate students to one of the frontiers of research, while keeping the prerequisites to a minimum, because most of the theory in the book requires only prior knowledge of Calculus and a University Physics course.




The Cosmology of Extra Dimensions and Varying Fundamental Constants


Book Description

The workshop on The Cosmology of Extra Dimensions and Varying Fundamental Constants, which was part of JENAM 2002, was held at the Physics Department of the University of Porto (FCUP) from the 3rd to the 5th of September 2002. It was regularly attended by about 110 participants, of which 65 were officially registered in the VFC workshop, while the others came from the rest of the JENAM workshops. There were also a few science correspondents from the national and international press. During the 3 days of the scientific programme, 8 Invited Reviews and 30 Oral Communications were presented. The speakers came from 11 different European countries, and also from Argentina, Australia, Canada, Japan and the U.S.A. There were also speakers from six Portuguese research institutions, and nine of the speak ers were Ph.D. students. The contributions are presented in these proceedings in chronological order. The workshop brought together string theorists, particle physicists, theoretical and observational cosmologists, relativists and observational astrophysicists. It was generally agreed that this inter-disciplinarity was the greatest strength of the work shop, since it provided people coming into this very recent topic from the various different backgrounds with an opportunity to understand each other's language and thereby gain a more solid understanding of the overall picture.




Just Six Numbers


Book Description

How did a single "genesis event" create billions of galaxies, black holes, stars and planets? How did atoms assemble -- here on earth, and perhaps on other worlds -- into living beings intricate enough to ponder their origins? What fundamental laws govern our universe?This book describes new discoveries and offers remarkable insights into these fundamental questions. There are deep connections between stars and atoms, between the cosmos and the microworld. Just six numbers, imprinted in the "big bang," determine the essential features of our entire physical world. Moreover, cosmic evolution is astonishingly sensitive to the values of these numbers. If any one of them were "untuned," there could be no stars and no life. This realization offers a radically new perspective on our universe, our place in it, and the nature of physical laws.




Fundamental Parameters in Cosmology


Book Description




The Fundamental Constants


Book Description

The speed of light, the fine structure constant, and Newton's constant of gravity ? these are just three among the many physical constants that define our picture of the world. Where do they come from? Are they constant in time and across space? In this book, physicist and author Harald Fritzsch invites the reader to explore the mystery of the fundamental constants of physics in the company of Isaac Newton, Albert Einstein, and a modern-day physicist. The conversation that the three scientists are imagined to have provides an entertaining introduction to the constants and covers topics ranging from atomic, nuclear, and particle physics to astrophysics and cosmology.




Euclidean Quantum Gravity


Book Description

The Euclidean approach to Quantum Gravity was initiated almost 15 years ago in an attempt to understand the difficulties raised by the spacetime singularities of classical general relativity which arise in the gravitational collapse of stars to form black holes and the entire universe in the Big Bang. An important motivation was to develop an approach capable of dealing with the nonlinear, non-perturbative aspects of quantum gravity due to topologically non-trivial spacetimes. There are important links with a Riemannian geometry. Since its inception the theory has been applied to a number of important physical problems including the thermodynamic properties of black holes, quantum cosmology and the problem of the cosmological constant. It is currently at the centre of a great deal of interest.This is a collection of survey lectures and reprints of some important lectures on the Euclidean approach to quantum gravity in which one expresses the Feynman path integral as a sum over Riemannian metrics. As well as papers on the basic formalism there are sections on Black Holes, Quantum Cosmology, Wormholes and Gravitational Instantons.




Cosmological Parameters and the Evolution of the Universe


Book Description

How old is our Universe? At what speed is our Universe expanding? Is our universe flat or curved? How is the hierarchical structure of the present Universe formed? The purpose of IAU Symposium 183 on the Cosmological Parameters and the Evolution of the Universe was to encourage a state-of-the-art discussion and assessment of cosmology by putting together the latest observational data and theoretical ideas on the evolution of the universe and cosmological parameters. In this volume, excellent reviews on these subjects by distinguished scientists are included. The first article by M.S. Longair, `Cosmological Parameters and the Evolution of the Universe: Progress and Prospect', is a magnificent general review which can be understood by non-specialists. The other reviews include Hubble Constants (W.L. Freedman, G.A. Tammann), Microwave Background Radiation (R.B. Partridge, N. Sugiyama), Galaxy Formation and Evolution (R.S. Ellis) and Alternative Cosmological Models (J.V. Narlikar). In addition to the reviews, recent observational and theoretical developments by outstanding active scientists are included.




A new standard model of cosmology: Time-varying fundamental constants and the evolution of the universe


Book Description

A new theoretical framework is presented to explain the evolution of the universe based on the time-varying properties of the fundamental constants. A static universe with time-varying constants can explain the origin of the cosmic microwave background radiation, CMB anisotropies, the CMB cold spot, the observed redshift-distance modulus data, the origin and composition of dark matter in the universe, galaxy cluster mass estimates, Milky Way galaxy luminosity estimates, population II stellar properties, vacuum-photon interactions, energy cycling between matter, radiation and vacuum field components, time-varying Higgs mechanism and particle mass, and the observed matter-antimatter dichotomy. This is a complete theoretical framework that explains the observable universe and resolves many of the issues with modern-day cosmology.