Dimension reduction in metric geometry represents a finite collection of points in a space of smaller dimension while controlling their distances. The permitted error is measured by metric embedding distortion. The representing function need not be a linear transformation.
For ,
integer
, and
, let
be the least coordinate dimension
in which every
-point subset of any real Lp-space
can be represented with metric embedding
distortion at most
. The target is
, with norm
.