On the Non-linear Scale of Cosmological Perturbation Theory

On the Non-linear Scale of Cosmological Perturbation Theory PDF Author: Diego Blas
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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On the Non-linear Scale of Cosmological Perturbation Theory

On the Non-linear Scale of Cosmological Perturbation Theory PDF Author: Diego Blas
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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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.

Cosmological Perturbations

Cosmological Perturbations PDF Author: Román Scoccimarro
Publisher:
ISBN:
Category : Nonlinear theories
Languages : en
Pages : 90

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Dark Energy and the Formation of the Large Scale Structure of the Universe

Dark Energy and the Formation of the Large Scale Structure of the Universe PDF Author: Jérôme Gleyzes
Publisher: Springer
ISBN: 3319412108
Category : Science
Languages : en
Pages : 124

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Book Description
This thesis presents several significant new results that shed light on two major puzzles of modern cosmology: the nature of inflation, the very early phase of the universe that is thought to have given rise to the large-scale structures that we observe today; and that of the current accelerated expansion. In particular, it develops a clean method for characterizing linear cosmological perturbations for general theories where gravity is modified and/or affected by a new component, called dark energy, responsible for the accelerated expansion. It proposes a new extension to what were long thought to be the most general scalar field theories devoid of instabilities, and demonstrates the robustness of the relation between the energy scale of inflation and the predicted amplitude of gravitational waves. Finally, it consolidates a set of consistency relations between correlation functions of the cosmological density field and investigates the phenomenological consequences of their potential violation. Presented in a clear, succinct and rigorous style, each of these original results is both profound and important and will leave a deep mark on the field.

Post-Planck Cosmology

Post-Planck Cosmology PDF Author: Cédric Deffayet
Publisher: OUP Oxford
ISBN: 0191044652
Category : Science
Languages : en
Pages : 569

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Book Description
This book gathers the lecture notes of the 100th Les Houches Summer School, which was held in July 2013. These lectures represent a comprehensive pedagogical survey of the frontier of theoretical and observational cosmology just after the release of the first cosmological results of the Planck mission. The Cosmic Microwave Background is discussed as a possible window on the still unknown laws of physics at very high energy and as a backlight for studying the late-time Universe. Other lectures highlight connections of fundamental physics with other areas of cosmology and astrophysics, the successes and fundamental puzzles of the inflationary paradigm of cosmic beginning, the themes of dark energy and dark matter, and the theoretical developments and observational probes that will shed light on these cosmic conundrums in the years to come.

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 : 143

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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.

Non-Linear Cosmological Perturbations

Non-Linear Cosmological Perturbations PDF Author: Hooshyar Assadullahi
Publisher:
ISBN:
Category :
Languages : en
Pages :

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The Young Universe

The Young Universe PDF Author: Richard Taillet
Publisher: John Wiley & Sons
ISBN: 1394169574
Category : Science
Languages : en
Pages : 356

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Book Description
The Young Universe presents four major physical and astrophysical themes related to these extreme phases of the primordial universe. In particular, it presents the physics of the primordial plasma and the concepts of quantum and particle physics necessary to describe this extreme state. It discusses the cosmological background radiation and explores inflation, an extremely rapid expansion phase that is believed to have occurred very early in cosmological history and to have shaped our present universe. The book also provides a synthesis of the dark matter problem.

Particles, Strings and Cosmology

Particles, Strings and Cosmology PDF Author: Kiwoon Choi
Publisher: Springer Science & Business Media
ISBN: 9780735402959
Category : Science
Languages : en
Pages : 510

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Book Description
PASCOS is an interdisciplinary symposium on the interface of of Particle physics, String theory and Cosmology. Over the past two decades these three disciplines have increasingly become closer. Historically there was always a strong overlap between particle physics and cosmology. This connection has become even stronger with the realization that some of the fundamental issues in cosmology such as the presence of dark matter and dark energy may possibly find a resolution only via new theories of particle physics. At the same time string theory has begun to play an increasingly important role in particle physics as a possible framework for building unified models of particle interaction including gravity. In recent years we have seen an increasing overlap between cosmology and string theory and currently the area of string cosmology is one of the most active fields of research. PASCOS 2005 aimed to provide coherent discussions of recent developments on the interface of the three disciplines and also on their interconnections. In particular, superstring aspects in low energy particle theory (SUSY) and cosmological applications (moduli stabilization) are extensively covered in this volume. Topics include dark matter and dark energy, baryogenesis, flavor and CP violation, neutrino physics, supersymmetry and extra dimensions, flux compactification, string model building, as well as brane cosmology.

Modern Cosmological Observations and Problems

Modern Cosmological Observations and Problems PDF Author: Gregory Bothun
Publisher: CRC Press
ISBN: 1000162710
Category : Science
Languages : en
Pages : 324

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Book Description
In recent years an enormous amount of cosmological data has come from well known projects such as the Hubble Space Telescope (HST) and the Cosmic Background Explorer (COBE). This book explains and makes sense of this vast array of new observational data in terms of its impact on current cosmological models. With new theories and a plethora of data feeding cosmology in the 1990s, Gregory Bothun sets about the task of re- assessing our cosmological models. He outlines exactly what the latest observations are, and how they should be seen as either consistent or in conflict with current cosmogenic scenarios. In this search for a reconciliation of current data with competing theory, he explains how Einstein's idea of a cosmological constant has now become a viable hypothesis. This authoritative text should be valuable to all those studying cosmological observations at advanced undergraduate or beginning graduate level. Bothun draws a path through cosmology by defining a trajectory that is based on the data. This should also provide a framework for professional cosmologists and related readers in physics as it presents a solid observational foundation which either supports or conflicts with present theory. The book is illustrated including many CCD images of galaxies. Given the rapidly changing nature of the field, this book is supported by a World Wide Web site of supplementary material that is designed to readily update the material in the book.