Diffuse supernova neutrinos at underground laboratories
  I review the physics of the Diffuse Supernova Neutrino flux (or Background,
DSNB), in the context of future searches at the next generation of neutrino
observatories. The theory of the DSNB is discussed in its fundamental elements,
namely the cosmological rate of supernovae, neutrino production inside a core
collapse supernova, redshift, and flavor oscillation effects. The current upper
limits are also reviewed, and results are shown for the rates and energy
distributions of the events expected at future liquid argon and liquid
scintillator detectors of O(10) kt mass, and water Cherenkov detectors up to a
0.5 Mt mass. Perspectives are given on the significance of future observations
of the DSNB, both at the discovery and precision phases, for the investigation
of the physics of supernovae and of the properties of the neutrino.
