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 14 of 14 for “"de Sitter Space"”.
-
Violating the Weak Cosmic Censorship Conjecture in Asymptotically Anti-de Sitter Space-Times
… Our results suggest that in both cases the space-time curvature can be made to grow without bound in a region visible to distant observers by imposing sufficiently violent boundary conditions on the metric or gauge field. In the electromagnetic case, this only happens at zero temperature, …
-
Numerical simulations of instabilities in general relativity
General relativity, one of the pillars of our understanding of the universe, has been a remarkably successful theory. It has stood the test of time for more than 100 years and has passed all experimental tests so far. Most recently, the LIGO collaboration made the first-ever direct detection of …
-
Supersymmetry at the dawn of the LHC era
… context of anomaly mediation in supergravity, I demonstrate how goldstino couplings can be used as a probe of the underlying symmetry structure of unbroken SUSY in anti-de Sitter space. When multiple SUSY-breaking occurs and goldstini comprise most of the dark matter in the universe, I find a new …
-
Infinite derivative gravity : a ghost and singularity-free theory
… at later times. To this end, an infinite derivative extension of relativity is introduced, with the gravitational action derived and the non-linear field equations calculated, before being linearised around both Minkowski space and de Sitter space. The theory is then constrained so as to …
-
Non-Relativistic Holography from Horava Gravity
… explored example of this tool is the correspondence between general relativity on five dimensional Anti-de Sitter space and a four dimensional supersymmetric Yang-Mills theory. This case is extremely useful as the strong coupling regime of the Yang-Mills theory is solved by weakly coupled …
-
Theoretical and experimental approaches to the dark energy and the cosmological constant problem.
… In this dissertation the problem and a set of widely-discussed theoretical solutions to this problem are reviewed. It is shown that a recently developed Lorentz gauge theory of gravity can provide a natural solution. In this theory presented here, the metric is not dynamical and it is shown that …
-
Topics in quantum field theory and holography
… of this thesis, we will study free fermions as models for topological insulators, on gravitational backgrounds which include both torsion and curvature, in d = 2 + 1 and d = 4 + 1 dimensions. We compute the parity-odd effective actions for these systems, and use these effective actions to deduce …
-
Supersymmetric backgrounds of M-theory and AdS4/CFT3 correspondence
… of a warped product of four-dimensional anti-de-Sitter space with a sevendimensional Riemannian manifold Y7. We show that the necessary and sufficient conditions for supersymmetry can be phrased in terms of a local SU(2)-structure on Y7. Solutions with non-zero M2-brane charge also admit a …
-
Aspects of twistors and tractors in field theory
This thesis is divided into three sections. The first begins with a review of the Fefferman-Graham embedding space construction and the closely-related tractor calculus, which provides a simple way to catalogue and invent conformally invariant operators. In particular, the conformal wave operator …
-
Early Seeds and Cosmic Skies: Quantum Origins of the Universe and Insights from Large-Scale Structure
… form the backbone of the current cosmological model. Collectively, they paint a picture of a universe's structure sourced by quantum fluctuations and then billions of years of gravitational clustering in an expanding universe. These concepts are illustrated in Part I, which serves as an …
-
The Phase of the Cosmological Wavefunction
… and locality form a vital foundation for our descriptions of fundamental physics. Their implications for particle physics are well established, through, for instance, the spin–statistics theorem, the optical theorem, and the CPT theorem. In contrast, their role in quantum interactions in …
-
Die Methode der nichtlokalen effektiven Wirkung in höherdimensionalen Raumzeitmodellen
Among the most promising candidates for a unified description of quantum <br>theory and gravitation is superstring theory. It predicts the existence of <br>multidimensional stable objects called "branes" (short for membranes). On <br>these branes open strings can end, which also means that the …
-
Relativistic and non-relativistic holography
Holography is one of the most interesting developments in String theory in the past few years. In this thesis, we discuss various aspects of the correspondence at the phenomenological and conceptual levels. At the phenomenological level, holographic duals of strong coupling QCD-like boundary …
-
An Exploration of AdS3 Gravity as a Holographic Theory
… of quantum gravity which states that the description of a volume of space can be encoded on a lower-dimensional boundary to the region. One such example is that of the Bekenstein-Hawking entropy of a black hole, which states the remarkable fact that the entropy of a black hole is simply …