Accelerating Expansion

Accelerating Expansion
Author: Gordon Belot
Publisher: Oxford University Press
Total Pages: 241
Release: 2023-08-24
Genre: Mathematics
ISBN: 019286646X

Accelerating Expansion explores some of the philosophical implications of modern cosmology, focused on the significance that the discovery of the accelerating expansion of the Universe has for our understanding of time, geometry, and physics. The appearance of the cosmological constant in the equations of general relativity allows one to model universes in which space has an inherent tendency towards expansion. This constant, introduced by Einstein but subsequently abandoned by him, returned to centre stage with the discovery of the accelerating expansion. This pedagogically-oriented essay begins with a study of the most basic and elegant relativistic world that involves a positive cosmological constant, de Sitter spacetime. It then turns to the relatives of de Sitter spacetime that dominate modern relativistic cosmology. Some of the topics considered include: the nature of time and simultaneity in de Sitter worlds; the sense in which de Sitter spacetime is a powerful dynamical attractor; the limited extent to which observation can give us information about the topology of space in a world undergoing accelerated expansion; and cosmologists' favourite sceptical worry about the reliability of evidence and the possibility of knowledge, the problem of Boltzmann brains.

The Accelerating Expansion of the Universe

The Accelerating Expansion of the Universe
Author: Paul F. Kisak
Publisher: Createspace Independent Publishing Platform
Total Pages: 280
Release: 2017-07-15
Genre:
ISBN: 9781974013395

11.3 billion years ago a star exploded. It is framed by the constellation Ursa Major. It was photographed in 1997 and it's impact on cosmology theory is still being felt. This exploding star is the Supernova 1997ff type Ia. The discovery and analysis of the radiation that emanates from SN 1997ff is providing support for the theory of "The Accelerating Expansion of our Universe," "Dark Matter," and "Dark Energy." The Hubble discovery also reveals that the universe only recently began speeding up, a discovery that suggests the universe is expanding more quickly than in the past, but there were alternate explanations. The accelerating expansion of the universe is the observation that the universe appears to be expanding at an increasing rate, so that the velocity at which a distant galaxy is receding from the observer is continuously increasing with time. The accelerated expansion was discovered in 1998, by two independent projects, the Supernova Cosmology Project and the High-Z Supernova Search Team, which both used distant type Ia supernovae as standard candles to measure the acceleration. The expansion of the universe is thought to have been accelerating since the universe entered its dark-energy-dominated era roughly 5 billion years ago. Within the framework of general relativity, an accelerating expansion can be accounted for by a positive value of the cosmological constant (Lambda), equivalent to the presence of a positive vacuum energy, dubbed "dark energy." While there are alternative possible explanations, the description assuming dark energy (positive Lambda) is used in the current standard model of cosmology, which also includes cold dark matter (CDM) and is known as the Lambda-CDM model. This book focuses on our Accelerating universe and the theories that support it.This book is designed to be a state of the art, superb academic reference work and provide an overview of the topic and give the reader a structured knowledge to familiarize yourself with the topic at the most affordable price possible. The accuracy and knowledge is of an international viewpoint as the edited articles represent the inputs of many knowledgeable individuals and some of the most current knowledge on the topic, based on the date of publication.

The Accelerating Universe

The Accelerating Universe
Author: Mario Livio
Publisher: Turner Publishing Company
Total Pages: 282
Release: 2008-05-02
Genre: Science
ISBN: 0470356294

Advance Praise for The Accelerating Universe "The Accelerating Universe is not only an informative book about modern cosmology. It is rich storytelling and, above all, a celebration of the human mind in its quest for beauty in all things." —Alan Lightman, author of Einstein's Dreams "This is a wonderfully lucid account of the extraordinary discoveries that have made the last years a golden period for observational cosmology. But Mario Livio has not only given the reader one clear explanation after another of what astronomers are up to, he has used them to construct a provocative argument for the importance of aesthetics in the development of science and for the inseparability of science, art, and culture." —Lee Smolin, author of The Life of the Cosmos "What a pleasure to read! An exciting, simple account of the universe revealed by modern astronomy. Beautifully written, clearly presented, informed by scientific and philosophical insights." —John Bahcall, Institute for Advanced Study "A book with charm, beauty, elegance, and importance. As authoritative a journey as can be taken through modern cosmology." —Allan Sandage, Observatories of the Carnegie Institution of Washington

Lectures on Cosmology

Lectures on Cosmology
Author: Georg Wolschin
Publisher: Springer
Total Pages: 188
Release: 2010-03-10
Genre: Science
ISBN: 364210598X

The lectures that four authors present in this volume investigate core topics related to the accelerated expansion of the Universe. Accelerated expansion occured in the ?36 very early Universe – an exponential expansion in the in ationary period 10 s after the Big Bang. This well-established theoretical concept had rst been p- posed in 1980 by Alan Guth to account for the homogeneity and isotropy of the observable universe, and simultaneously by Alexei Starobinski, and has since then been developed by many authors in great theoretical detail. An accelerated expansion of the late Universe at redshifts z

Accelerated Cosmic Expansion

Accelerated Cosmic Expansion
Author: Claudia Moreno González
Publisher: Springer Science & Business Media
Total Pages: 223
Release: 2013-11-29
Genre: Science
ISBN: 3319020633

Proceedings from the 2012 Fourth International Meeting on Gravitation and Cosmology, focusing on accelerated cosmic expansion This volume provides both an update and a review of the state of alternative theories of gravity in connection with the accelerated expansion of the universe issue. Different theoretical proposals exist to explain the acceleration in the cosmic expansion, generating the dark energy issue and opening the possibility to theories of gravity alternative to general relativity. Related issues such as the dark matter problem are also surveyed in order to give the readers profound insight on the subject from different points of view. Comprised of short talks and plenary lectures given by leading experts in the field, some of them with brilliant and historic contributions, the book allows the reader to find readable and referenced surveys in topics like f(R) theories, the dark matter and dark energy issues, Modified Newtonian Dynamics (MOND) scenarios, f(T) theories, scalar-tensor theories derived from non-Riemannian geometries, emergent universes, the cosmological constant and other topics of current interest for younger and senior physicists and graduate students. These proceedings are from the Fourth International Meeting on Gravitation and Cosmology, held in Guadalajara, Jalisco, México, from 20 - 25 May, 2012, was sponsored by ICTP- Trieste, Italy and COECyTJAL-Universidad de Guadalajara, México. This event is a series of scientific meetings started in 2004 in Cuba, focusing on current and selected topics in the fields of gravitation and cosmology.

Expansion of the Universe

Expansion of the Universe
Author: Steff Jaywan
Publisher: Dedona Publishing
Total Pages: 43
Release:
Genre: Science
ISBN:

The universe is a vast and enigmatic expanse, filled with countless mysteries that have intrigued scientists and philosophers for centuries. One of the most profound discoveries of modern cosmology is that the universe is not only expanding but doing so at an accelerating rate. This revelation has reshaped our understanding of the cosmos and introduced the concept of dark energy as a dominant force driving this acceleration. In this book, we embark on a journey through the history of cosmological thought, from the early observations that hinted at an expanding universe to the groundbreaking discoveries that revealed its acceleration. We will explore the role of the cosmological constant, a term introduced by Einstein in his equations of General Relativity, which has come to be associated with dark energy. We begin with a foundational understanding of the universe's expansion, delving into the Big Bang theory and the key observations that support it. From there, we examine the pivotal role of the cosmological constant and its implications for the structure and fate of the universe. As we navigate through the complexities of dark energy and its various theoretical models, we will also address the challenges and alternative theories that scientists are exploring to explain this cosmic acceleration. Finally, we will consider the future of cosmological research, highlighting the ongoing quests to unravel the mysteries that still elude us.

Cosmology and Particle Astrophysics

Cosmology and Particle Astrophysics
Author: Lars Bergström
Publisher: Springer Science & Business Media
Total Pages: 375
Release: 2006-05-26
Genre: Science
ISBN: 3540329242

Beginning with basic facts about the observable universe, this book reviews the complete range of topics that make up a degree course in cosmology and particle astrophysics. The book is self-contained - no specialised knowledge is required on the part of the reader, apart from undergraduate math and physics. This paperback edition targets students of physics, astrophysics and cosmology from advanced undergraduate to early graduate level.

The Extravagant Universe

The Extravagant Universe
Author: Robert P. Kirshner
Publisher: Princeton University Press
Total Pages: 313
Release: 2016-09-13
Genre: Science
ISBN: 1400883806

The Extravagant Universe tells the story of a remarkable adventure of scientific discovery. One of the world's leading astronomers, Robert Kirshner, takes readers inside a lively research team on the quest that led them to an extraordinary cosmological discovery: the expansion of the universe is accelerating under the influence of a dark energy that makes space itself expand. In addition to sharing the story of this exciting discovery, Kirshner also brings the science up-to-date in a new epilogue. He explains how the idea of an accelerating universe--once a daring interpretation of sketchy data--is now the standard assumption in cosmology today. This measurement of dark energy--a quality of space itself that causes cosmic acceleration--points to a gaping hole in our understanding of fundamental physics. In 1917, Einstein proposed the "cosmological constant" to explain a static universe. When observations proved that the universe was expanding, he cast this early form of dark energy aside. But recent observations described first-hand in this book show that the cosmological constant--or something just like it--dominates the universe's mass and energy budget and determines its fate and shape. Warned by Einstein's blunder, and contradicted by the initial results of a competing research team, Kirshner and his colleagues were reluctant to accept their own result. But, convinced by evidence built on their hard-earned understanding of exploding stars, they announced their conclusion that the universe is accelerating in February 1998. Other lines of inquiry and parallel supernova research now support a new synthesis of a cosmos dominated by dark energy but also containing several forms of dark matter. We live in an extravagant universe with a surprising number of essential ingredients: the real universe we measure is not the simplest one we could imagine.