Stress tensors from trace anomalies in conformal field theories

Using trace anomalies, we determine the vacuum stress tensors of arbitrary even-dimensional conformal field theories in Weyl flat backgrounds. We demonstrate a simple relation between the Casimir energy on R×S^d-1 and the type A anomaly coefficient. This relation generalizes earlier results in two and four dimensions. These field-theory results for the Casimir energy are shown to be consistent with holographic predictions in two, four, and six dimensions.