Physical Sciences and Mathematics Commons^™

Using Natural Phenomena To Study The Ionosphere, Joseph Benjamin Malins

Physics & Astronomy ETDs

This dissertation explores novel techniques for observing the ionosphere using natural signals. The ionosphere is a region of plasma hundreds of kilometers above the Earth that affects communication and remote sensing applications across the world. Traditional techniques for observing the ionosphere involve using man made radio signals, either to reflect the signal at HF frequencies or to pass several signals through the ionosphere and compare the difference the ionosphere makes in the signals. However, such techniques are limited by the ability of equipment to produce these signals and by the numerous laws and regulations governing transmission of signals in the …

Searching For Supermassive Binary Black Holes And Their Gravitational Waves, Karishma Bansal

Physics & Astronomy ETDs

The recent discovery of gravitational waves (GWs) by the LIGO collaboration has opened a new observing window on the universe, but it is limited to the GWs in the frequency range of 10-1000 Hz. The main motivation of this thesis is to consider the possibility of detecting low frequency (nHz) GWs. In the pursuit of these waves, we need to understand their source of origin and build a detector with the required sensitivity. Low-frequency waves are expected as a result of coalescing binary supermassive black holes (SMBBHs). We hope to detect these waves in the near future using pulsar timing …

Measuring Deterministic And Stochastic Gravitational Waves With Pulsar Timing Array Experiments, Kristina Islo

Theses and Dissertations

Pulsar timing arrays (PTAs) are uniquely poised to detect the nanohertz-frequency gravitational waves from supermassive black hole binaries (SMBHBs) formed during galaxy merger. Efforts are underway to observe three species of gravitational signal from these systems: the stochastic ensemble, individual, adiabatic binary inspirals, and bursts with memory. This dissertation discusses all three.

A typical Bayesian search for evidence of a stochastic gravitational wave background from the superposition of many unresolvable SMBHB inspirals requires weeks to months to deliver results. This is due in part to the inclusion of inter-pulsar spatial and temporal correlations induced in PTA data by such a …