  The expectation values of energy density and pressure of a quantum field
inside a wedge-shaped region appear to violate the expected relationship
between torque and total energy as a function of angle. In particular, this is
true of the well-known Deutsch--Candelas stress tensor for the electromagnetic
field, whose definition requires no regularization except possibly at the
vertex. Unlike a similar anomaly in the pressure exerted by a reflecting
boundary against a perpendicular wall, this problem cannot be dismissed as an
artifact of an ad hoc regularization.
