Gravitational waves from binary black holes as probes of the structure
  formation history
  Gravitational-wave detectors on earth have detected gravitational waves from
merging compact objects in the local Universe. In future we will detect
gravitational waves from higher-redshift sources, which trace the high-redshift
structure formation history. That is, by observing high-redshift
gravitational-wave events we will be able to probe structure formation history.
This will provide additional insight into the early Universe when primordial
fluctuations are generated and also into the nature of dark matter.
