  The Precision IceCube Next Generation Upgrade (PINGU) is a proposed
low-energy in-fill extension to the IceCube Neutrino Observatory. With
detection technology modeled closely on the successful IceCube example, PINGU
will provide a 6Mton effective mass for neutrino detection with an energy
threshold of a few GeV. With an unprecedented sample of over 60,000 atmospheric
neutrinos per year in this energy range, PINGU will make highly competitive
measurements of neutrino oscillation parameters in an energy range over an
order of magnitude higher than long-baseline neutrino beam experiments. PINGU
will measure the mixing parameters $\theta_{\rm 23}$ and $\Delta m^2_{\rm 32}$,
including the octant of $\theta_{\rm 23}$ for a wide range of values, and
determine the neutrino mass ordering at $3\sigma$ median significance within 4
years of operation. PINGU's high precision measurement of the rate of
${\nu_\tau}$ appearance will provide essential tests of the unitarity of the
$3\times 3$ PMNS neutrino mixing matrix. PINGU will also improve the
sensitivity of searches for low mass dark matter in the Sun, use neutrino
tomography to directly probe the composition of the Earth's core, and improve
IceCube's sensitivity to neutrinos from Galactic supernovae. Reoptimization of
the PINGU design has permitted substantial reduction in both cost and
logistical requirements while delivering performance nearly identical to
configurations previously studied. This document summarizes the results of
detailed studies described in a more comprehensive document to be released
soon.
