Browsing Physics and Astronomy by Supervisor "Afshordi, Niayesh"
Now showing items 118 of 18

Amended Model of Large Scale Dark Matter Structure
(University of Waterloo, 20200903)Dark matter makes up around a quarter of the total energy density in the universe, but its identity remains elusive. Current ways of studying dark matter have centered around its macroscopic properties, such as density ... 
Aspects of Nonlocality: from Particles to Black Holes
(University of Waterloo, 20160506)This dissertation is a collection of works on different aspects of the following subjects: causal setcontinuum correspondence, wave propagation on causal sets, nonlocal quantum field theory, potential connection between ... 
Black holes in cosmological spacetimes and alternative theories of gravity
(University of Waterloo, 20230809)This thesis is dedicated to the study of spacetimes surrounding black holes within the context of cosmology, high energy physics and modified theories of gravity. We do this by applying and adapting modern numerical ... 
Charged Black Hole Solutions in Alternative Theories of Gravity
(University of Waterloo, 20160906)In my thesis, I examine charged black holes in two contexts. The first part covers the formation of something analogous to event horizons for a class of LorentzViolating theories which allow for signals to travel faster ... 
Cosmological beam plasma instabilities
(University of Waterloo, 20170824)Blazars are the main source of extragalactic very high energy gammarays. These gamma rays annihilate on the extragalactic background light, producing electronpositron pair beams with TeV energies. The pair beams are very ... 
Cosmological Tests of Causal Set Phenomenology
(University of Waterloo, 20170920)Causal Set Theory is an approach to Quantum Gravity that postulates that the fundamental structure of a spacetime manifold is a Lorentz Invariant discrete structure endowed with a causal order from which the geometry and ... 
Dark Matter and Neutrinos in the Foggy Universe
(University of Waterloo, 20190107)Dark matter is predicted to be the main contribution to the matter content in the universe, in addition to ordinary baryonic matter such as protons and neutrons. However, we are limited in our knowledge of the nature of ... 
Entanglement Entropy of Scalar Fields in Causal Set Theory
(University of Waterloo, 20170815)Entanglement entropy is now widely accepted as having deep connections with quantum gravity. It is therefore desirable to understand it in the context of causal sets, especially since they provide the UV cutoff needed to ... 
Neutron Stars, the Exotica  From Modifying General Relativity to Strong Magnetic Fields
(University of Waterloo, 20151222)The gravitational aether theory is a modification of General Relativity that decouples vacuum energy from gravity, and thus can potentially address the cosmological constant problem. The classical theory is distinguishable ... 
New Views on the Cosmological Big Bang
(University of Waterloo, 20170920)This dissertation is a collection of four different proposals to describe the early universe. Each will draw from insights of different areas of physics to suggest a description which differs from the standard inflationary ... 
Probing Dark Matter from the Galaxy to the Cosmic Web
(University of Waterloo, 20200123)Dark matter, although invisible, accounts for the majority of matter of the universe. How this invisible component affects cosmic structure formation is one of the primary lines of inquiry in physical cosmology, and the ... 
Probing the dark universe with gravitational lensing
(University of Waterloo, 20180917)Since its early success as an experimental test of the theory of general relativity in 1919, gravitational lensing has come a long way and is firmly established as an indispensable element for many astrophysical applications. ... 
The quantum and the gravity: Newtonian and Cosmological applications
(University of Waterloo, 20180718)The gravitational decoherence field studies the suppression of coherence in quantum systems caused by effects rooted in the gravitational interaction. This models are not just important to yield interesting ideas about the ... 
Quantum Aspects of Black Holes: From Microstates to Echoes and Somewhere InBetween
(University of Waterloo, 20230523)In this thesis we explore quantum aspects of black holes from a variety of perspectives. In part I of this thesis we are motivated by the black hole information paradox to explore the idea of gravitational wave echoes ... 
Quantum Black Holes in the Sky
(University of Waterloo, 20200930)Black Holes are possibly the most enigmatic objects in our Universe. From their detection in gravitational waves upon their mergers, to their snapshot eating at the centres of galaxies, black hole astrophysics has undergone ... 
Quantum Information across Spacetime: From Gravitational Waves to Spinning Black Holes
(University of Waterloo, 20210820)This thesis is split into two parts. In the first part, we investigate BoseEinstein condensates (BECs) as a means to detect gravitational waves. For the detection of continuous gravitational waves, we study its sensitivity ... 
Studying the largest scales in the Universe with the kinetic SunyaevZel'dovich effect
(University of Waterloo, 20220119)As we progress further into the era of precision cosmology, new avenues to test our fundamental models of the Universe are opening up. This Ph.D. thesis is concerned with the development and understanding of a technique ... 
Unifying Thermal Big Bang and Black Holes
(University of Waterloo, 20200930)Theories that stand the test of constant bombardment of new (and old) ideas, observations and unexplained phenomena are hard to come by. Despite countless attempts over many years of trying, cosmology and gravitational ...