Theoretical and Observational Consistency of Massive Gravity

Theoretical and Observational Consistency of Massive Gravity PDF Author: Lavinia Heisenberg
Publisher: Springer
ISBN: 3319189352
Category : Science
Languages : en
Pages : 212

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Book Description
This work is a detailed study of both the theoretical and phenomenological consequences of a massive graviton, within the ghost-free theory of massive gravity, the de Rham-Gabadadze-Tolley (dRGT) theory. Its aim is to test the physical viability of the theory. It begins by putting constraints on the parameters of the theory in the decoupling limit based on purely theoretical grounds, like classical stability in the cosmological evolution of self-accelerating and degravitating solutions. The author then constructs a proxy theory to massive gravity from the decoupling limit resulting in non-minimally coupled scalar-tensor interactions as an example of a subclass of Horndeski theories. Lastly, she addresses the natural question of whether the parameters introduced in the dRGT theory are subject to strong renormalization by quantum loops and shows how the non-renormalization theorem protects the graviton mass from quantum corrections. Beyond the decoupling limit the quantum corrections are found to be proportional to the graviton mass, proving its technical naturalness.

Theoretical and Observational Consistency of Massive Gravity

Theoretical and Observational Consistency of Massive Gravity PDF Author: Lavinia Heisenberg
Publisher: Springer
ISBN: 3319189352
Category : Science
Languages : en
Pages : 212

Get Book Here

Book Description
This work is a detailed study of both the theoretical and phenomenological consequences of a massive graviton, within the ghost-free theory of massive gravity, the de Rham-Gabadadze-Tolley (dRGT) theory. Its aim is to test the physical viability of the theory. It begins by putting constraints on the parameters of the theory in the decoupling limit based on purely theoretical grounds, like classical stability in the cosmological evolution of self-accelerating and degravitating solutions. The author then constructs a proxy theory to massive gravity from the decoupling limit resulting in non-minimally coupled scalar-tensor interactions as an example of a subclass of Horndeski theories. Lastly, she addresses the natural question of whether the parameters introduced in the dRGT theory are subject to strong renormalization by quantum loops and shows how the non-renormalization theorem protects the graviton mass from quantum corrections. Beyond the decoupling limit the quantum corrections are found to be proportional to the graviton mass, proving its technical naturalness.

Modified Gravity and Cosmology

Modified Gravity and Cosmology PDF Author: Emmanuel N. Saridakis
Publisher: Springer Nature
ISBN: 3030837157
Category : Science
Languages : en
Pages : 631

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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.

Modifications of Einstein's Theory of Gravity at Large Distances

Modifications of Einstein's Theory of Gravity at Large Distances PDF Author: Eleftherios Papantonopoulos
Publisher: Springer
ISBN: 331910070X
Category : Science
Languages : en
Pages : 435

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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.

Astroparticle Physics and Cosmology

Astroparticle Physics and Cosmology PDF Author: Subhendra Mohanty
Publisher: Springer Nature
ISBN: 3030562018
Category : Science
Languages : en
Pages : 296

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Book Description
Cosmology and astroparticle physics have seen an avalanche of discoveries in the past decade (IceCube - high energy neutrinos, LIGO - gravitational waves, Fermi- gamma-ray telescope, Xenon-1T - dark matter detection, PLANCK- cosmic microwave radiation, EHT picture of black hole, SDSS -galaxy surveys), all of which require a multidisciplinary background for analyzing the phenomena. The arena for testing particle physics models is in the multimessenger astronomical observations and at the same time cosmology now requires a particle physics basis for explaining many phenomena. This book discusses the theoretical tools of particle physics and general relativity which are essential for understanding and correlating diverse astronomical observations.

Seventh Marcel Grossmann Meeting, The: On Recent Developments In Theoretical And Experimental General Relativity, Gravitation, And Relativistic Field Theories - Proceedings Of The 7th Marcel Grossmann Meeting (In 2 Parts)

Seventh Marcel Grossmann Meeting, The: On Recent Developments In Theoretical And Experimental General Relativity, Gravitation, And Relativistic Field Theories - Proceedings Of The 7th Marcel Grossmann Meeting (In 2 Parts) PDF Author: Ruffini Remo
Publisher: World Scientific
ISBN: 9814550000
Category :
Languages : en
Pages : 2024

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Book Description
Since 1975, the triennial Marcel Grossmann Meetings have been organized in order to provide opportunities for discussing recent advances in gravitation, general relativity and relativisitic field theories, emphasizing mathematical foundations, physical predictions, and experimental tests.The proceedings of the Seventh Marcel Grossmann Meeting include the invited papers given at the plenary sessions, the summaries of the parallel sessions, the contributed papers presented at the parallel sessions, and the evening public lectures.The authors of these papers discuss many of the recent theoretical, observational, and experimental developments that have significant implications for the fields of physics, cosmology, and relativistic astrophysics.

Proceedings of the International Conference on Two Cosmological Models

Proceedings of the International Conference on Two Cosmological Models PDF Author:
Publisher: Plaza y Valdes
ISBN: 6074025304
Category :
Languages : en
Pages : 410

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Book Description


Graphs and Patterns in Mathematics and Theoretical Physics

Graphs and Patterns in Mathematics and Theoretical Physics PDF Author: Mikhail Lyubich
Publisher: American Mathematical Soc.
ISBN: 0821836668
Category : Mathematics
Languages : en
Pages : 443

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Book Description
The Stony Brook Conference, "Graphs and Patterns in Mathematics and Theoretical Physics", was dedicated to Dennis Sullivan in honor of his sixtieth birthday. The event's scientific content, which was suggested by Sullivan, was largely based on mini-courses and survey lectures. The main idea was to help researchers and graduate students in mathematics and theoretical physics who encounter graphs in their research to overcome conceptual barriers. The collection begins with Sullivan's paper, "Sigma models and string topology," which describes a background algebraic structure for the sigma model based on algebraic topology and transversality. Other contributions to the volume were organized into five sections: Feynman Diagrams, Algebraic Structures, Manifolds: Invariants and Mirror Symmetry, Combinatorial Aspects of Dynamics, and Physics. These sections, along with more research-oriented articles, contain the following surveys: "Feynman diagrams for pedestrians and mathematicians" by M. Polyak, "Notes on universal algebra" by A. Voronov, "Unimodal maps and hierarchical models" by M. Yampolsky, and "Quantum geometry in action: big bang and black holes" by A. Ashtekar. This comprehensive volume is suitable for graduate students and research mathematicians interested in graph theory and its applications in mathematics and physics.

Theory and Observational Limits in Cosmology

Theory and Observational Limits in Cosmology PDF Author: William R. Stoeger
Publisher:
ISBN:
Category : Astronomy
Languages : en
Pages : 588

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Book Description


Gravitational Waves

Gravitational Waves PDF Author: Ajit Kembhavi
Publisher: Springer Nature
ISBN: 9811557098
Category : Science
Languages : en
Pages : 181

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Book Description
Gravitational waves were first predicted by Albert Einstein in 1916, a year after the development of his new theory of gravitation known as the general theory of relativity. This theory established gravitation as the curvature of space-time produced by matter and energy. To be discernible even to the most sensitive instruments on Earth, the waves have to be produced by immensely massive objects like black holes and neutron stars which are rotating around each other, or in the extreme situations which prevail in the very early ages of the Universe. This book presents the story of the prediction of gravitational waves by Albert Einstein, the early attempts to detect the waves, the development of the LIGO detector, the first detection in 2016, the subsequent detections and their implications. All concepts are described in some detail, without the use of any mathematics and advanced physics which are needed for a full understanding of the subject. The book also contains description of electromagnetism, Einstein’s special theory and general theory of relativity, white dwarfs, neutron stars and black holes and other concepts which are needed for understanding gravitational waves and their effects. Also described are the LIGO detectors and the cutting edge technology that goes into building them, and the extremely accurate measurements that are needed to detect gravitational waves. The book covers these ideas in a simple and lucid fashion which should be accessible to all interested readers. The first detection of gravitational waves was given a lot of space in the print and electronic media. So, the curiosity of the non-technical audience has been aroused about what gravitational waves really are and why they are so important. This book seeks to answer such questions.

Aspects of Quantum Theory

Aspects of Quantum Theory PDF Author: Paul Adrien Maurice Dirac
Publisher: Cambridge University Press
ISBN: 0521086000
Category : Science
Languages : en
Pages : 290

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Book Description
These twelve articles discuss aspects of quantum mechanics that owe their origin to the work of P. A. M. Dirac.