Cosmology, Relativity, and Gravity Commons^™

Tests Of General Relativity Through Searches For Lorentz And Cpt Symmetry Breaking, Kellie Ault

Doctoral Dissertations and Master's Theses

An effective field theory framework, the Standard Model Extension (SME), provides an agnostic, systematic test of General Relativity (GR) and its founding spacetime symmetries, Lorentz and CPT symmetry. Violating these symmetries may provide clues toward unifying the physics of the General Relativity and the Standard Model of particle physics. Part of this work involves the merge of theory, data analysis and experiments with gravitational wave (GW) signals from LIGO/Virgo/KAGRA (LVK) detectors. A modified dispersion relation derived from the SME of GWs is implemented into the LIGO Scientific Collaboration Algorithm Library Suite (LALSuite), where a joint Bayesian inference of the source …

Development And Testing Of A New Method For Velocity-Selecting White Dwarfs From Gaia By Galactic Population, Joseph Hammill

Doctoral Dissertations and Master's Theses

The detailed processes by which spiral galaxies form remains an open question in modern cosmology. Observations of the current configuration of spiral galaxies including the Milky Way reveal thin and thick disk and halo populations which must all be accounted for in formation theories and likely have distinct ages. Using the Milky Way as an example to probe this question, we are studying the formation history of these structures.

This work details our approach to age-dating the galaxy, velocity-selecting targets from a sample of white dwarfs from the Gaia DR3 catalog that have also been age-analysed using BASE-9. BASE-9 uses …

Gravity Wave And Turbulence Transport In The Mesopause Region, Yafang Guo

Doctoral Dissertations and Master's Theses

Vertical transport due to dissipating gravity waves and turbulence in the mesopause region (85-100 km) are analyzed with observational data obtained from a narrow-band sodium wind/temperature lidar located at Andes Lidar Observatory (ALO), Cerro Pach´on (30.25 S, 70.73 W), Chile. The Na lidar at ALO has been in regular operation since 2010. The upgrade of the lidar system in May 2014 resulted in great improvements of the signal levels, which enabled data acquisition of high temporal and vertical resolutions reaching 6 s and 25 m. Traditional data processing utilizes signals at lower resolutions, typically at 60 s and 500 m, …

Long-Range Propagation, Interaction, And Dissipation Of Small-Scale Gravity Waves In The Mesosphere And Lower Thermosphere, Christopher J. Heale

Doctoral Dissertations and Master's Theses

A 2-D nonlinear, compressible numerical model [Snively and Pasko, 2008] is used in conjunction with ray-theory to investigate the long-range propagation, dissipation and interaction of small-scale gravity waves in the Mesosphere and Lower Thermosphere (MLT) region. The research in this thesis is made up of three distinct studies which build upon each other. The first investigates the thermospheric dissipation of three gravity wave packets representing: (1) A quasi-monochromatic packet, (2) A monochromatic, steady state wave, and (3) A spectrally broad packet, as well as an initial condition specified packet. It is found that dissipation due to molecular viscosity and …