On Fri, 8 Aug 2003, Bilge wrote:

Mike Helland:
You are incorrect. My bias is Quantum, not classical.

In that case, curvature should not be a problem. Quantum field
theory makes use of curvature tensors for quantum fields. The
electromagnetic field strength tensor F^uv is the curvature tensor
for the electromagnetic field. Maxwell's equations a

d_{u}F^{uv} = j^{u}

along with the bianchi identity:

d^w F^uv + d^v F^wu + d^v F^uw = 0

The electromagnetic field strength tensor is obtained in exactly the
same way as the gravitational field strength tensor - from the commutator
of covariant derivatives. The equivalent quantity in gravity is the
riemann tensor.

Sorry to keep hasseling you, but are you saying that in a Yang-Mills
theory, that the "curvature" that comes from using the gauge covariant
derivative is the field strength tensor?

I really need to recheck out Gauge Fields Knots & Gravity from our
library...

--
William C. Hogg