Well Kip. Thorne and S.Hawking believe that the Kasimir effect is a case of negative energy density but nevertheless the point was that negative energy densities have nothing incompatible with GR, GR has nothing to say about the sign of energy densities, that's why people invented the energy...
The Warp Drive doesn't violate GR, it requires negative energy density but that's not a law of GR.
There are the so called energy conditions, weak, strong and null and I think that only the weak energy condition forbids negative energy density, this conditions are not part of general relativity...
I think my problem wasn't really clear, this tensor is supposed to be a stress energy tensor and therefore it should be symmetric but I'm finding that it isn't Ttr /= Trt. I'm not sure if I'm differentiating wrong the complex scalar field or I think originally instead of partial derivatives they...
Hi , I am working with the following stress-energy tensor:
T\mu\nu=\partial\mu\phi\partial\nu\phi* - g\mu\nu(\nabla\mu\phi\nabla\mu\phi* - m2\phi\phi*)
Where \phi is a complex scalar of the form:
\phi(r,t) = \psi(r)eiwt
that obeys the Klein-gordon equation and \phi* is the complex...