Let
T be a piecewise expanding interval map and
be an abstract perturbation of
T into an interval map with a hole. Given a number
,
, we compute an upper-bound on the size of a hole needed for the existence of an absolutely continuous conditionally invariant measure (accim) with escape rate not greater than
. The two main ingredients of our approach are
... [Show full abstract] Ulam's method and an abstract perturbation result of Keller and Liverani. Comment: 15 pages