Light or Dark? Mass and Gravity in the Universe – Stacy McGaugh

Date: Thu. September 5th, 2013, 4:15 pm-5:15 pm
Location: Rockefeller 301

We now have a well developed cosmological paradigm, LCDM, in which most of the mass-energy is composed of unknown dark components. This picture provides a satisfactory description of large scale structure but has serious failings on the small scales of individual galaxies. Simultaneously, we have some unlikely successes of an alternative theory of gravity, MOND, in predicting the dynamical behavior of galaxies while offering little in the way of a cosmology. Neither theory obviously subsumes the other, posing a dilemma with profound implications.