  IceCube-Gen2 is a planned extension of the IceCube Neutrino Observatory at
the South Pole. The extension is optimized to search for sources of
astrophysical neutrinos from TeV to EeV, and will improve the sensitivity of
the observatory to neutrino point sources by a factor of five. The science case
of IceCube-Gen2 is built on a successful decade of observations with IceCube.
This index of contributions to the 37th International Cosmic Ray Conference in
Berlin, Germany (12-23 July 2021) describes research and development efforts
for IceCube-Gen2. Included are performance studies of next-generation optical
sensors that will detect Cherenkov radiation from TeV-PeV cosmic rays and
neutrinos; optimizations of the geometries of the surface and in-ice optical
arrays; and estimates of the sensitivity of the proposed IceCube-Gen2 radio
array to Askaryan emission from PeV-EeV neutrinos. Contributions related to the
existing instrument, IceCube, are available in a separate collection.
