Gravitational wave probes of dark matter: challenges and opportunities
  In this white paper, we discuss the prospects for characterizing and
identifying dark matter using gravitational waves, covering a wide range of
dark matter candidate types and signals. We argue that present and upcoming
gravitational wave probes offer unprecedented opportunities for unraveling the
nature of dark matter and we identify the most urgent challenges and open
problems with the aim of encouraging a strong community effort at the interface
between these two exciting fields of research.
