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.
Results
Showing 1 to 10 of 10 for “"theoretical cosmology"”.
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The measure problem in eternal inflation
… measure problem, which is a major challenge of theoretical cosmology. In this thesis, I shall describe the measure problem and propose a promising candidate solution: the scale-factor cutoff measure. I shall study this measure in detail and show that it is free of the pathologies many other …
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Causality and unitarity in the early universe
… amplitudes and open quantum systems to cosmology and to understand how fundamental principles shape cosmological correlators. This thesis examines some of the outcomes of this effort. The first three chapters are an introduction to theoretical cosmology with standard material on …
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Cosmological dynamics of exponential gravity
… several hotly debated current issues in modern cosmology, with a focus on f(R) gravity. In chapter 1 we present a review of modern theoretical cosmology. We begin by introducing some fundamental cosmological concepts, followed by a discussion of the field equations of general relativity, which …
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Topics in cosmology: structure formation, dark energy and recombination
\indent The field of theoretical cosmology consists of numerous, inter-related branches, whose ambitious goal is to uncover the history of the universe from its beginning to its future. Achieving this, no doubt, requires a deep understanding of many areas of physics. In this thesis I touch upon a …
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Primordial evolution of cosmological perturbations: Theory and computation
This thesis discusses results in theoretical cosmology related to the primordial evolution of cosmological perturbations with the help of numerical analysis. Primordial fluctuations are thought to be the seeds of large-scale structure, therefore modelling their initial conditions and evolution is …
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Modified Gravity and Cosmology on the Largest Scales
… a series of my contributions to research in theoretical cosmology, focusing on aspects of the very large scale universe, particularly dark energy, cosmic acceleration, modified gravity, and cosmic variance. Following an overview of the current understanding of the standard cosmological model …
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Cosmic Echoes of the Early Universe: From Primordial Black Holes to Gravitational Waves
… this context that the era of observational and theoretical cosmology is coming into its own. In this thesis, we investigate gravitational and particle phenomena in the early universe. The power of this cosmological approach lies in the fact that, in the early universe, temperatures and pressures …
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Cosmological Perturbations in the Early Universe
<p>One essence in capturing the history of primordial fluctuations that arise during inflation and eventually lead to formation of large scale structures in the universe, relies on quantizing general relativity coupled to a scalar field. This is a system that respects diffeomorphism invariance, the …
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Tests of the Planck Cosmology at High and Low Redshifts
The inflationary ΛCDM cosmology currently provides an accurate description of the Universe. It has been tested using several observational techniques over a wide redshift range, and it provides a good fit to most of them. In addition, it is a surprisingly economical model, requiring only six …
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Spherically-symmetric inhomogeneities in general relativity and their effects in cosmology
… solutions are relevant in many areas of cosmology, from perturbations in the early Universe to growth of large scale structures in the later eras. In this thesis, we first focus on a comparison between the tetrad-based method and the widely used Lemaitre-Tolman-Bondi (LTB) model for …