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.