  The Precision IceCube Next Generation Upgrade (PINGU) is a proposed
low-energy in-fill array of the IceCube Neutrino Observatory. Leveraging
technology proven with IceCube, PINGU will feature the world's largest
effective volume for neutrinos at an energy threshold of a few GeV, improving
the sensitivity to several aspects of neutrino oscillation physics at modest
cost. With its unprecedented statistical sample of low-energy atmospheric
neutrinos, PINGU will have highly competitive sensitivity to $\nu_{\mu}$
disappearance, the $\theta_{23}$ octant, and maximal mixing, will make the
world's best $\nu_{\tau}$ appearance measurement, allowing a unique probe of
the unitarity of the PMNS mixing matrix, and will be able to distinguish the
neutrino mass ordering at $3\sigma$ significance with less than 4 years of
data. PINGU can also extend the indirect search for solar WIMP dark matter
complimentary to the on-going and planned direct dark matter experiments. At
the lower end of the energy range, PINGU may use neutrino tomography to
directly probe the composition of the Earth's core. With its increased module
density, PINGU will improve IceCube's sensitivity to galactic supernova
neutrino bursts and enable it to extract the neutrino energy spectral shape.
