David Coss
University of Missouri – St Louis
Advisor: Prof. Ricardo Flores, UMSL

Abstract
Dark matter has been one of the most thoroughly studied areas of cosmology. One of the most useful tools at the disposal of astrophysicists in studying dark matter in galaxies and galaxy clusters is Gravitational Lensing. Through the study of gravitational deflection of the light of background objects due to foreground (e.g. galactic) deflectors, one can obtain a two-dimensional mass density projection of the unseen matter comprising most of the mass of the universe. Ellipticity changes in the background objects provide a method of quantifying distortions of such objects. Shape changes, convergence and shear, provide a means to relate ellipticity to mass density. Two programs have been developed to simulate light ray deflection and the shearing effects of gravitational lensing. Such software will be used in further study to relate shear to mass density, with particular interest in the commonly accepted mass density model, the Navarro, Frenk and White (NFW) model.