A metric thickening of a given metric space
is any metric space admitting an isometric embedding of
.
Thickenings have found use in applications of topology to data analysis, where one
may approximate the shape of a dataset via the persistent homology of an increasing
sequence of spaces. We introduce two new families of metric thickenings, the
–Vietoris–Rips and
–Čech metric thickenings
for all
, which include all
probability measures on
whose
–diameter
or
–radius
is bounded from above, equipped with an optimal transport metric. The
–diameter
(resp. –radius) of a
measure is a certain
relaxation of the usual notion of diameter (resp. radius) of a subset of a metric space.
These families recover the previously studied Vietoris–Rips and Čech metric thickenings
when
.
As our main contribution, we prove a stability theorem for the persistent homology of
–Vietoris–Rips
and
–Čech
metric thickenings, which is novel even in the case
. In the
specific case
,
we prove a Hausmann-type theorem for thickenings of manifolds,
and we derive the complete list of homotopy types of the
–Vietoris–Rips
thickenings of the
–sphere
as the scale increases.