Aspects of galileons and generalised scalar-tensor theories

This thesis is devoted to the study of modified gravity theories, especially, the scalar-tensor theories. A theorem due to Weinberg which states, that the equivalence principle is a necessary consequence of Lorentz invariance in a gravitational theory described by spin-2 massless particles is presen...

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Main Author: Sivanesan, Vishagan
Format: Thesis (University of Nottingham only)
Language:English
Published: 2014
Subjects:
Online Access:https://eprints.nottingham.ac.uk/13500/
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author Sivanesan, Vishagan
author_facet Sivanesan, Vishagan
author_sort Sivanesan, Vishagan
building Nottingham Research Data Repository
collection Online Access
description This thesis is devoted to the study of modified gravity theories, especially, the scalar-tensor theories. A theorem due to Weinberg which states, that the equivalence principle is a necessary consequence of Lorentz invariance in a gravitational theory described by spin-2 massless particles is presented in Chapter 2. In view of this theorem modified gravity models either attempt to make \textit{graviton} massive or add other spin degrees of freedom. Scalar tensor theories are a simple and natural choice. An overview of some important scalar-tensor theories such as, Brans-Dicke model, DGP theory (although not a scalar-tensor theory it reduces to one in the so called \textit{decoupling} limit as we would see in chapter 2), Galileon model, Horndeski theory is also given in Chapter 2. The Hamiltonian analysis of the Galileon model is presented in Chapter 3. Chapter 4 presents the boundary terms and junction conditions of the Horndeski theory in the presence of codimension-1 branes. A generalised multiple-scalar-tensor theory analogous to Horndeski theory is developed in Chapter 5. We conclude with the proof of the most general multiple scalar field theory in arbitrary dimensions and flat-space time in Chapter 6. Chapters 3,4,5,6 are original work where the first 3 are based on the following journal articles.
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spelling nottingham-135002025-02-28T11:25:30Z https://eprints.nottingham.ac.uk/13500/ Aspects of galileons and generalised scalar-tensor theories Sivanesan, Vishagan This thesis is devoted to the study of modified gravity theories, especially, the scalar-tensor theories. A theorem due to Weinberg which states, that the equivalence principle is a necessary consequence of Lorentz invariance in a gravitational theory described by spin-2 massless particles is presented in Chapter 2. In view of this theorem modified gravity models either attempt to make \textit{graviton} massive or add other spin degrees of freedom. Scalar tensor theories are a simple and natural choice. An overview of some important scalar-tensor theories such as, Brans-Dicke model, DGP theory (although not a scalar-tensor theory it reduces to one in the so called \textit{decoupling} limit as we would see in chapter 2), Galileon model, Horndeski theory is also given in Chapter 2. The Hamiltonian analysis of the Galileon model is presented in Chapter 3. Chapter 4 presents the boundary terms and junction conditions of the Horndeski theory in the presence of codimension-1 branes. A generalised multiple-scalar-tensor theory analogous to Horndeski theory is developed in Chapter 5. We conclude with the proof of the most general multiple scalar field theory in arbitrary dimensions and flat-space time in Chapter 6. Chapters 3,4,5,6 are original work where the first 3 are based on the following journal articles. 2014-12-09 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/13500/1/thesis-vish2.pdf Sivanesan, Vishagan (2014) Aspects of galileons and generalised scalar-tensor theories. PhD thesis, University of Nottingham. modified gravity theories scalar-tensor theories gravitation gravitational theory galileon field theory
spellingShingle modified gravity theories
scalar-tensor theories
gravitation
gravitational theory
galileon field theory
Sivanesan, Vishagan
Aspects of galileons and generalised scalar-tensor theories
title Aspects of galileons and generalised scalar-tensor theories
title_full Aspects of galileons and generalised scalar-tensor theories
title_fullStr Aspects of galileons and generalised scalar-tensor theories
title_full_unstemmed Aspects of galileons and generalised scalar-tensor theories
title_short Aspects of galileons and generalised scalar-tensor theories
title_sort aspects of galileons and generalised scalar-tensor theories
topic modified gravity theories
scalar-tensor theories
gravitation
gravitational theory
galileon field theory
url https://eprints.nottingham.ac.uk/13500/