The concept of symmetry has widespread manifestations and many diverse applications-from architecture to mathematics to science. Yet, as twentieth-century physics has revealed, symmetry has a special, central role in nature, one that is occasionally and enigmatically violated. F…
X-ray surveys are an effective way to study growing supermassive black holes (SMBHs) in galaxy centers, as actively accreting SMBHs manifest themselves as active galactic nuclei (AGN) that can be observed in the X-ray in most cases. Through studying AGNs in X-ray survey fields t…
The detection of gravitational waves (GWs) originating from a black hole (BH) binary merger in 2015 by LIGO marked the beginning of the age of GW astronomy. Another defining moment came in 2017 with the joint detection of GWs and their electromagnetic (EM) counterpart, beginning…
While supermassive black holes (SMBHs) up to a billion times the mass of the Sun are found in the centers of all massive galaxies and stellar mass black holes of ~ 10 solar masses (M☉) are formed from supernovae, there is currently no direct evidence for intermediate mass black …
Galaxies have existed for the majority of the lifetime of the Universe, having first formed 400-1000 Myr after the Big Bang, and it is known that most galaxies contain supermassive black holes (SMBHs) at their centres. In recent years, correlations have been found between the ev…
Tells the story of the recent discoveries in astrophysics: black holes and the beginning of the expansion of the Universe; it also outlines what the future of the Universe may be.
I argue that the state inside an initially empty box with mirrored walls being quasistatically lowered from infinity toward a black hole is the Boulware state for that black hole. Using an expression for the stress-energy tensor from a moving mirror, which I derive specifically …
In this thesis we consider three topics: the Penrose inequality (PI), polymer corrected gravitational collapse, and zero mode excitations in a RandallSundrum-2 (RS2) cosmological braneworld model. In chapter 2, we attempt to construct a counterexample to the PI using prolate sph…
Accretion, the process by which matter collects into a central object, is ubiquitous and often dynamically important for astrophysical objects on the scale of compact object disks (∼ 1010 cm) up to that of galactic clusters (∼ 1024 cm). In order for matter to accrete, it must lo…