Dawson Huth


Date of Award

Spring 5-15-2023

Author's School

Graduate School of Arts and Sciences

Author's Department


Degree Name

Doctor of Philosophy (PhD)

Degree Type



Part I: The expectation of new physics motivates more stringent tests of our current best understanding of gravitation, General Relativity (GR). Many theories proposing new physics predict the violation of Einstein’s equivalence principle, a set of criteria which must hold for GR to be valid. A torsion balance instrument was designed and operated to detect any violation of the equivalence principle. The motivations for performing such an experi- ment, instrument design, operational principles, data collected and subsequent analysis are described in detail in this thesis. After 51 days of continuous data collection experimental upper bounds on the violation of the equivalence principle characterized by the Eötvös pa- rameters η⊙ = [0 ± 1.0] × 10−11 and ηDM = [0 ± 5.9] × 10−4 for violations associated with the Sun and dark matter at the Galactic Center has been made. Furthermore, bounds placed for the specific coupling to the baryon and lepton content of the torsion balance are presented.Part II: The spectra and composition of cosmic rays have been measured with increasing precision and accuracy for over a century. Recent observations of 60Fe in primary cosmic rays paves the way for a deeper theoretical study of cosmic ray transport and acceleration processes. A solution to a diffusion equation describing cosmic ray transport through the Galaxy is derived in the context of spatially and temporally continuous and discrete sources. Preliminary results of these solutions are shown and potential cosmic ray observables are discussed.


English (en)

Chair and Committee

Ramanath Cowsik

Committee Members

Henric Krawczynski, James Buckley, Michael Ogilvie, Bradley Jolliff,