Author: Emmanuel N. Saridakis Publisher: Springer Nature ISBN: 3030837157 Category : Science Languages : en Pages : 631
Book Description
With a focus on modified gravity this book presents a review of the recent developments in the fields of gravity and cosmology, presenting the state of the art, high-lighting the open problems, and outlining the directions of future research. General Relativity and the ΛCDM framework are currently the standard lore and constitute the concordance paradigm of cosmology. Nevertheless, long-standing open theoretical issues, as well as possible new observational ones arising from the explosive development of cosmology in the last two decades, offer the motivation and lead a large amount of research to be devoted in constructing various extensions and modifications. In this review all extended theories and scenarios are first examined under the light of theoretical consistency, and are then applied in various geometrical backgrounds, such as the cosmological and the spherical symmetric ones. Their predictions at both the background and perturbation levels, and concerning cosmology at early, intermediate and late times, are then confronted with the huge amount of observational data that astrophysics and cosmology has been able to offer in the last two decades. Theories, scenarios and models that successfully and efficiently pass the above steps are classified as viable and are candidates for the description of Nature, allowing readers to get a clear overview of the state of the art and where the field of modified gravity is likely to go. This work was performed in the framework of the COST European Action “Cosmology and Astrophysics Network for Theoretical Advances and Training Actions” - CANTATA.
Author: Eleftherios Papantonopoulos Publisher: Springer ISBN: 331910070X Category : Science Languages : en Pages : 426
Book Description
In the last few years modified gravity theories have been proposed as extensions of Einstein's theory of gravity. Their main motivation is to explain the latest cosmological and astrophysical data on dark energy and dark matter. The study of general relativity at small scales has already produced important results (cf e.g. LNP 863 Quantum Gravity and Quantum Cosmology) while its study at large scales is challenging because recent and upcoming observational results will provide important information on the validity of these modified theories. In this volume, various aspects of modified gravity at large scales will be discussed: high-curvature gravity theories; general scalar-tensor theories; Galileon theories and their cosmological applications; F(R) gravity theories; massive, new massive and topologically massive gravity; Chern-Simons modifications of general relativity (including holographic variants) and higher-spin gravity theories, to name but a few of the most important recent developments. Edited and authored by leading researchers in the field and cast into the form of a multi-author textbook at postgraduate level, this volume will be of benefit to all postgraduate students and newcomers from neighboring disciplines wishing to find a comprehensive guide for their future research.
Author: Baojiu Li Publisher: World Scientific Publishing Company ISBN: 9789813273993 Category : Science Languages : en Pages : 0
Book Description
Gravity beyond general relativity / Kazuya Koyama -- Parametrizations for tests of gravity / Lucas Lombriser -- Simulation techniques / Claudio Llinares -- Approximation methods in modified gravity models / Baojiu Li -- Large-scale structure probes of modified gravity / Catherine Heymans and Gong-Bo Zhao -- Tests of gravity with galaxy clusters / Matteo Cataneo -- Towards testing gravity with cosmic voids / Yan-Chuan Cai -- Astrophysical tests of screened modified gravity / Jeremy Sakstein -- Laboratory constraints / Philippe Brax.
Author: Salvatore Capozziello Publisher: Springer Science & Business Media ISBN: 9400701659 Category : Science Languages : en Pages : 428
Book Description
Beyond Einstein’s Gravity is a graduate level introduction to extended theories of gravity and cosmology, including variational principles, the weak-field limit, gravitational waves, mathematical tools, exact solutions, as well as cosmological and astrophysical applications. The book provides a critical overview of the research in this area and unifies the existing literature using a consistent notation. Although the results apply in principle to all alternative gravities, a special emphasis is on scalar-tensor and f(R) theories. They were studied by theoretical physicists from early on, and in the 1980s they appeared in attempts to renormalize General Relativity and in models of the early universe. Recently, these theories have seen a new lease of life, in both their metric and metric-affine versions, as models of the present acceleration of the universe without introducing the mysterious and exotic dark energy. The dark matter problem can also be addressed in extended gravity. These applications are contributing to a deeper understanding of the gravitational interaction from both the theoretical and the experimental point of view. An extensive bibliography guides the reader into more detailed literature on particular topics.
Author: Baojiu Li Publisher: World Scientific ISBN: 9813274018 Category : Science Languages : en Pages : 324
Book Description
Modified gravity theories have been a main focus of theoretical cosmology research in the past decade or so, and have been quickly developing into a mature research field that attracts attention, interest and effort from both theoretical and observational cosmologists. To be prepared for fully exploiting the future observational data, and to provide a guidance for people who are new to this field, it is useful to have a comprehensive review to summarise the current state of knowledge and to foresee the future developments.This book presents expert reviews on different topics in the field, which are then coordinated and organised in a self-consistent and self-contained manner. It is suitable for graduate students and researchers interested in the frontier research of gravity theories.
Author: Jonathan Pearson Publisher: Springer Science & Business Media ISBN: 331901210X Category : Science Languages : en Pages : 200
Book Description
When predictions of Einstein's theory of General Relativity are compared against observations of our Universe, a huge inconsistency is found. The most popular fix for this inconsistency is to "invent" around 94% of the content of the universe: dark matter and dark energy. The dark energy is some exotic substance responsible for the apparent observed acceleration of the Universe. Another fix is to modify the theory of gravity: it is entirely plausible that Einstein's theory of General Relativity breaks down on cosmological scales, just as Newton's theory of gravity breaks down in the extreme gravitational field of the Sun. There are many alternative theories of gravity, each with the aim of describing observations of our Universe where General Relativity fails. Whether it is dark energy or some modified theory of gravity, it is clear that there is some "dark sector" in the Universe. In this thesis the author constructs a unifying framework for understanding the observational impact of general classes of dark sector theories, by formulating equations of state for the dark sector perturbations.
Author: Alexandre Barreira Publisher: Springer ISBN: 3319336967 Category : Science Languages : en Pages : 218
Book Description
This unique thesis covers all aspects of theories of gravity beyond Einstein’s General Relativity, from setting up the equations that describe the evolution of perturbations, to determining the best-fitting parameters using constraints like the microwave background radiation, and ultimately to the later stages of structure formation using state-of-the-art N-body simulations and comparing them to observations of galaxies, clusters and other large-scale structures. This truly ground-breaking work puts the study of modified gravity models on the same footing as the standard model of cosmology. Since the discovery of the accelerating expansion of the Universe, marked by the awarding of the 2011 Nobel Prize in Physics, there has been a growing interest in understanding what drives that acceleration. One possible explanation lies in theories of gravity beyond Einstein’s General Relativity. This thesis addresses all aspects of the problem, an approach that is crucial to avoiding potentially catastrophic biases in the interpretation of upcoming observational missions.
Author: Georg Wolschin Publisher: Springer ISBN: 364210598X Category : Science Languages : en Pages : 200
Book Description
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
Author: Tiberiu Harko Publisher: Cambridge University Press ISBN: 1108428746 Category : Science Languages : en Pages : 475
Book Description
Presents a detailed analysis of modified theories of gravity, discussing their development, cosmological and astrophysical implications and outstanding challenges.
Author: Emmanuel N. Saridakis
Author: Eleftherios Papantonopoulos
Author: Baojiu Li
Author: Salvatore Capozziello
Author: Baojiu Li
Author: Timothy Clifton
Author: Jonathan Pearson
Author: Alexandre Barreira
Author: Georg Wolschin
Author: Tiberiu Harko