A coarse invariant for all metric spaces
  "An invariant of metric spaces under bornologous equivalences" gives an invariant and "A coarse invariant" extends the invariant to coarse equivalences. In both papers the invariant is defined for a class of metric spaces called sigma stable. This paper extends the invariant to all metric spaces and also gives an example of a space that is not sigma stable. 
Michael DeLyser, Brendon LaBuz, and Benjamin Wetsell
math.GN