Effective Field Theory, Black Holes, and the Cosmological Constant

Bekenstein has proposed the bound $S\le \pi M_P^2{L}^2$ on the total entropy $S$ in a volume $L^3$. This nonextensive scaling suggests that quantum field theory breaks down in large volume. To reconcile this breakdown with the success of local quantum field theory in describing observed particle phenomenology, we propose a relationship between UV and IR cutoffs such that an effective field theory should be a good description of nature. We discuss implications for the cosmological constant problem. We find a limitation on the accuracy which can be achieved by conventional effective field theory.