Metric Markov cotype is a property of a metric space that controls the smoothing of functions on finite
reversible Markov chains. A metric
space
has metric Markov cotype
with constant
if, for every positive integer
and
, every stochastic matrix
with probability
vector
satisfying
,
and every
,
...,
,
there are
,
...,
such that
The least possible
is denoted
(Mendel and Naor 2013). The points
may leave the subset containing
the original
,
which is why the property need not pass to subsets.
For ,
this smoothing property supports Lipschitz
extension problem results with Hilbert space
sources.