Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 11 of 11 for “"Cosmic inflation"”.
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Vector fields during cosmic inflation: stability analysis and phenomenological signatures.
… is based on the study of vector fields during cosmic inflation. Cosmic inflation has proven to be an accurate description of the very early universe, not only because of its success in resolving the classical problems of big bang cosmology, but also for introducing a natural mechanism for the …
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Probes of cosmic inflation: from the CMB to quantum analogues
… simulation methods to probe the physics of inflation, a brief period of exponential expansion thought to have occurred a fraction of a second after the Big Bang. Although inflation provides the initial conditions for standard cosmological evolution and the seeds for structure formation, its …
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Initial Conditions for Cosmic Inflation, the History of the Dark Sector, and Dark-Onium
The question remains whether inflation is robust to inhomogeneous initial conditions. This thesis first describes the basics of cosmic inflation and the evolution of primordial inhomogeneities in the matter field and spacetime metric during inflation. Then a new approach for analyzing the onset of …
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Aspects of Quantum Fluctuations under Time-dependent External Influences
… effects. The first part of this Thesis addresses cosmic inflation, where the quantum fluctuations of the inflaton field freeze and get amplified in the expanding universe. Afterwards, we turn our attention towards Bose-Einstein condensates, a laboratory system. Since most of our calculations are …
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Multifield inflation and differential geometry
Cosmic inflation posits that the universe underwent a period of exponential expansion, driven by one or several quantum fields, shortly after the Big Bang. Renormalization requires the fields be non-minimally coupled to gravity. We examine such multifield models and find a rich geometric structure. …
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Supersymmetry, supergravity, and String Theory based inflationary cosmology
… is to investigate and present an overview of inflationary theory. As part of this effort, the main motivations for cosmic inflation, which are known as problems in the standard big bang scenario, are reviewed. These problems are the "flatness problem", "horizon problem", and the "monopole …
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Preheating in multifield inflation
The theory of cosmic inflation was proposed to address problems with Standard Big Bang cosmology. The theory suggests the existence of an epoch during which the universe underwent an exponential expansion, followed by an epoch of slower expansion. Realistic models of high-energy physics require …
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Exploring The Universe With The Atacama Cosmology Telescope: Polarization-Sensitive Measurements Of The Cosmic Microwave Background
… the past twenty-five years, observations of the Cosmic Microwave Background (CMB) temperature fluctuations have served as an important tool for answering some of the most fundamental questions of modern cosmology: how did the universe begin, what is it made of, and how did it evolve? More …
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Polishing the Lenses: Refined Modelling of Gravitational Lensing and Delensing of the Cosmic Microwave Background
The cosmic microwave background (CMB) is made up of photons, the majority of which last scattered with electrons during the era of cosmic recombination, at redshift z~1100. They have been travelling, virtually undisturbed, ever since. Along their journey, however, the photons' paths are deflected …
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Galaxy groups from observations and simulations
… in the Universe. Together with the theory of cosmic inflation, this model makes a clear prediction for the initial conditions for structure formation and predicts that structures grow hierarchically through gravitational instability. As a result, small structures collapse first and eventually …
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Constraining the kinetically dominated Universe: Bayesian methods and primordial cosmology
… primordial perturbations from a nite amount of cosmic in ation. It is demonstrated how a pre-in ationary stage that is kinetically dominated causes features in the primordial power spectrum. These features can be associated with cosmological parameters, which are then constrained using Bayesian …