The entropy bound for local quantum field theory

We investigate the entropy bound for local quantum field theory in this Letter. Both the bosonic and fermionic fields confined to an asymptotically flat space-time are examined. By imposing the non-gravitational collapse condition, we find both of them are limited by the same entropy bound A3/4, where A is the boundary area of the region where the quantum fields are contained in. The gap between this entropy bound and the holographic entropy has been verified.