STRIDES is a broad external collaboration of the Dark Energy Survey, primarily aimed at finding ~100 gravitationally lensed quasars in the Dark Energy Survey. Strongly lensed quasars can be used to measure cosmological parameters, but we are limited by the small sample size of lenses with accurate time delays as well as all the other required ancillary datasets to make such measurements. According to Oguri & Marshall (2010, MNRAS, 405, 2579) there should be approximately 120 such lenses brighter than i=21 (third faintest image), including 20 high information-content quads, to be discovered in DES. By finding these lenses, STRIDES will contribute to advancements in the understanding of dark energy as well as addressing many other key questions in astrophysics.

Main Science Goals:

-Dark Energy from 100 gravitationally lensed quasars with time delays (distance precision and accuracy equivalent to dH_0 < 1%)

-Dark matter substructure from flux ratio anomalies, as measured from active galactic nuclei narrow line region, dusty tori, and radio emission.