The translative covering density of a convex body
is the infimum of the asymptotic upper densities of coverings
of Euclidean space by translates
of
.
Let
have only finitely many points in each bounded
set, let
, and require
, where the sum is a Minkowski
sum. Then
where
denotes
-dimensional
volume,
is the number of centers
in the hypercube
, and
is the supremum limit.
The density counts overlaps with multiplicity.
The same infimum can be taken over periodic coverings with centers , where
is a full-rank point lattice
and
is a finite set of distinct coset representatives. Such a covering has density
, where
is the covolume.
The number of cosets is unrestricted. Requiring just one
coset gives the lattice
covering density
, so
.
Rogers (1957) proved the upper bound
for every convex body with
, where
denotes the natural logarithm.
For instance, the hypercube
has translative covering density 1.