Traces of Exotic Physics in Cosmology

Abstract

In recent years it has become increasingly clear that our universe is far more intricate than we might ever have imagined. While theoretical formulations of the fundamental aspects of Nature have, for many years, hinted at its vast and elusive complexity, suggesting that our known world is but a tiny facet of the greater reality in which it is embedded, it has only been within the last several decades that observations have really begun to confirm this. Indeed, while deep-field surveys of the universe have uncovered myriads of galaxies, constituting an untold number of gravitationally bound microcosms such as ours, precision cosmological measurements have revealed that all of this luminous baryonic matter is a near negligible fraction of the total energy and matter in the universe. The vast majority of our cosmos is a dark universe, comprised of some kind of invisible substances or dark fluids that only interact gravitationally with visible matter.

Even among the objects that are visible to us, there are many mysterious entities which are predicted by theory and which may or may not as yet have been glimpsed in the cosmos. In the first part of this thesis we will study the interactions between two such entities, namely cosmic strings and rotating black holes. In the latter part, we will turn to the invisible sector and explore whether or not the dark phenomena in the universe could in fact be the shadows of fundamental objects moving in higher dimensions beyond our own.