Logarithmically concave sampling is the problem of generating a random vector whose law approximates a specified logarithmically
concave distribution. One oracle model specifies a
twice continuously differentiable
potential with
,
, and
Here
is a positive integer,
is the identity matrix,
and
is the Hessian of
.
The relation
means that
is a positive
semidefinite matrix. The target probability
density is
,
with
. An exact first-order oracle
query returns
and its gradient
. Real random
variables and unrestricted computation between
queries are allowed.