The Environmental Dependence of Dynamical and Lensing Mass Differences

Recent work in modified gravity suggests there should be observable, environmentally dependent differences between the lensing and dynamical masses of elliptical galaxies. Using a sample of previously identified lensing galaxies at redshifts between 0.1 and 0.3 from SDSS DR8, we define a density of neighboring galaxies using SDSS photometric redshifts for volumes of differing radii. We then compare the differences between dynamical and lensing masses with environment and compare to the numerical simulations.