Physics Commons^™

Weyl Gravity As A Gauge Theory, Juan Teancum Trujillo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A gauge theory is a theory in which the governing functional, known as the action, remains invariant under a continuous group of local transformations that form its symmetry. Each of the known fundamental interactions in the universe, such as electricity and magnetism, can be explained as arising from a particular gauge theory. Gravitation is no exception. Just as calculus can be used to find the value of a variable that maximizes or minimizes a function, calculus of variations can be used to find the equations, known as the field equations, that extremize the action, and these are the main equations …

Computational Efficiency Of A Hybrid Mass Concentration And Spherical Harmonic Modeling, Nathan Piepgrass

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Through Spherical Harmonics, one can describe complex gravitational fields. However as the order and degree of the spherical harmonics increases, the computation speed rises exponentially. In addition, for onboard applications of spherical harmonics, the processors are radiation hardened in order to mitigate negative effects of the space environment on electronics. But, those processors have outdated processing speeds, resulting in a slower onboard spherical harmonic program.

This thesis examines a partial solution to the slow computation speed of spherical harmonics programs. The partial solution was to supplant the gravity models in the flight software. The spherical harmonics gravity model can be …