Evidence for a large (R ~ 300 Mpc) local under-density and the implications for cosmology
Ryan Keenan



In Keenan et al. 2013, we presented a measurement of the near-infrared luminosity density as a function of distance from our position in the local universe. Our results indicated that the local universe appears under-dense by roughly 35% on radial scales of a few hundred megaparsecs, compared to more distant volumes probed in our study. Cosmological models have shown that a local under-density of this scale and amplitude could significantly bias measurements of the local expansion rate, and thereby artificially drive up our estimates of the Hubble constant and dark energy density. In this talk, I will present our updated results that include much wider area coverage on the sky from UKIDSS + SDSS as well as our own deeper spectroscopy that allow us to measure the K-band luminosity function at z > 0.1 to 2.5 magnitudes fainter than L* (resolving ~90% of the total light / stellar mass density). With these new data in hand our main result from 2013 holds and is made significantly more robust to cosmic variance with the larger volumes probed. I will present these new analyses and briefly sketch our plans to use our newly measured radial density profile of the local universe as input to an inhomogeneous cosmological model.