Gauge-invariant Cosmological Perturbation Theory

Gauge-invariant Cosmological Perturbation Theory PDF Author: Ruth Durrer
Publisher:
ISBN:
Category :
Languages : en
Pages : 134

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Gauge-invariant Cosmological Perturbation Theory

Gauge-invariant Cosmological Perturbation Theory PDF Author: Ruth Durrer
Publisher:
ISBN:
Category :
Languages : en
Pages : 134

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Gauge Invariant Cosmological Perturbation Theory

Gauge Invariant Cosmological Perturbation Theory PDF Author: Ruth Durrer
Publisher:
ISBN: 9782884491112
Category :
Languages : en
Pages : 131

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Manifestly Gauge-invariant Cosmological Perturbation Theory

Manifestly Gauge-invariant Cosmological Perturbation Theory PDF Author: Thomas Zilker
Publisher:
ISBN:
Category :
Languages : en
Pages : 102

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Gauge Invariant Perturbation Theory in Spatially Homogeneous Cosmology

Gauge Invariant Perturbation Theory in Spatially Homogeneous Cosmology PDF Author: Robert Theodore Jantzen
Publisher:
ISBN:
Category :
Languages : en
Pages : 228

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Cosmological Perturbation Theory in a Matter-time Gauge

Cosmological Perturbation Theory in a Matter-time Gauge PDF Author: Mustafa Saeed
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
This work examines cosmological perturbations in a Hamiltonian framework with a matter-time gauge. Einstein’s field equations are written in a matter-time gauge. The perturbed three-metric of cosmology, its conjugate momentum and the shift are substituted in these equations. The equations of motion of the perturbations to linear order are derived. These equations are expanded in terms of spatial Fourier modes and are then decomposed into scalar, vector and tensor components. After fixing gauges and solving constraints we find that the scalar mode is ultra local and that the vector modes vanish. We also see that the traceless transverse tensor modes give the known propagation equation for gravitational waves in an expanding, spatially flat, homogeneous and isotropic background.

Covariant and Gauge-invariant Analysis of Cosmological Perturbations in the Presence of a Primordial Magnetic Field

Covariant and Gauge-invariant Analysis of Cosmological Perturbations in the Presence of a Primordial Magnetic Field PDF Author: Christos G. Tsagas
Publisher:
ISBN:
Category :
Languages : en
Pages :

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The Vector Mode in the Second-order Cosmological Perturbation Theory

The Vector Mode in the Second-order Cosmological Perturbation Theory PDF Author: Shohei Saga
Publisher: Springer
ISBN: 9811080070
Category : Science
Languages : en
Pages : 136

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Book Description
This thesis sheds valuable new light on the second-order cosmological perturbation theory, extensively discussing it in the context of cosmic microwave background (CMB) fluctuations. It explores the observational consequences of the second-order vector mode, and addresses magnetic field generation and the weak lensing signatures, which are key phenomena of the vector mode. The author demonstrates that the second-order vector mode, which never appears at the linear-order level, naturally arises from the non-linear coupling of the first-order scalar modes. This leads to the remarkable statement that the vector-order mode clearly contributes to the generation of cosmological magnetic fields. Moreover, the weak lensing observations are shown to be accessible to the vector mode. On the basis of ongoing and forthcoming observations, the thesis concludes that the second-order vector mode is detectable.

Delta N Formalism In Cosmological Perturbation Theory

Delta N Formalism In Cosmological Perturbation Theory PDF Author: Ali Akbar Abolhasani
Publisher: World Scientific
ISBN: 9813238771
Category : Science
Languages : en
Pages : 182

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Book Description
Early Universe cosmology is an active area of research and cosmic inflation is a pillar of modern cosmology. Among predictions of inflation, observationally the most important one is the generation of cosmological perturbations from quantum vacuum fluctuations that source all inhomogeneous structures in the Universe, not to mention the large-scale structures such as clusters of galaxies.Cosmological perturbation theory is the basic tool to study the perturbations generated from inflation. There are a few different approaches to primordial cosmological perturbations. In the conventional approach one perturbs the field equations and after quantizing the perturbations by the use of the corresponding action, one calculates the power spectrum of cosmological observables. This approach extends to higher order perturbations such as bispectrum etc., but the analysis becomes increasingly difficult.The delta N formalism, the topic of this book, is an alternative approach. The novelty of this approach is that, under the condition that the scale of interest is very large so that the spatial derivatives may be ignored in the dynamics, it can be applied to all orders in perturbation theory and has a rigorous foundation in general relativity. Thanks to the fact that one can evaluate perturbations with only the knowledge of background solutions, it is proved to be much easier than the conventional approach in evaluating higher order effects in many cases.

Cosmology in Gauge Field Theory and String Theory

Cosmology in Gauge Field Theory and String Theory PDF Author: D. Bailin
Publisher: CRC Press
ISBN: 9781420057003
Category : Science
Languages : en
Pages : 332

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Book Description
Cosmology in Gauge Field Theory and String Theory focuses on the cosmological implications of the gauge theories of particle physics and of string theory. The book first examines the universe's series of phase transitions in which the successive gauge symmetries of the higher-temperature phase were spontaneously broken after the big bang, discussing relics of these phase transitions, more generic relics (baryons, neutrinos, axions), and supersymmetric particles (neutralinos and gravitinos). The author next studies supersymmetric theory, supergravity theory, and the constraints on the underlying field theory of the universe's inflationary era. The book concludes with a discussion of black hole solutions of the supergravity theory that approximates string theory at low energies and the insight that string theory affords into the microscopic origin of the Bekenstein-Hawking entropy. Cosmology in Gauge Field Theory and String Theory provides a modern introduction to these important problems from a particle physicist's perspective. It is intended as an introductory textbook for a first course on the subject at a graduate level.

Metric Theories of Gravity

Metric Theories of Gravity PDF Author: Alexander N. Petrov
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110383403
Category : Science
Languages : en
Pages : 621

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Book Description
By focusing on the mostly used variational methods, this monograph aspires to give a unified description and comparison of various ways of constructing conserved quantities for perturbations and to study symmetries in general relativity and modified theories of gravity. The main emphasis lies on the field-theoretical covariant formulation of perturbations, the canonical Noether approach and the Belinfante procedure of symmetrisation. The general formalism is applied to build the gauge-invariant cosmological perturbation theory, conserved currents and superpotentials to describe physically important solutions of gravity theories. Meticulous attention is given to the construction of conserved quantities in asymptotically-flat spacetimes as well as in asymptotically constant curvature spacetimes such as the Anti-de Sitter space. Significant part of the book can be used in graduate courses on conservation laws in general relativity. THE SERIES: DE GRUYTER STUDIES IN MATHEMATICAL PHYSICS The series is devoted to the publication of monographs and high-level texts in mathematical physics. They cover topics and methods in fields of current interest, with an emphasis on didactical presentation. The series will enable readers to understand, apply, and develop further, with sufficient rigor, mathematical methods to given problems in physics. The works in this series are aimed at advanced students and researchers in mathematical and theoretical physics. They can also serve as secondary reading for lectures and seminars at advanced levels.