"Bill Hobba" wrote in message
...
| I am reviewing QFT by going through An Introduction to Quantum Field
Theory
| by George Sterman and came across the section on Normal Ordering. I
| understand that only the energy differences are observable so it is ok to
| subtract the zero point energies. However the text does mention something
| that has been bothering me for some time. It states - 'We ignore the
| question of whether this is consistent with a theory of gravity' (page
44).
|
| Of course a infinite zero point energy would mean an infinite
gravitational
| field so their does seem to be a problem here. However it would seem
| inexorably tied up with cosmological constant problem which my
understanding
| is still a mystery. Does anyone know the latest take on the issue? Is it
| believed super-symmetry solves the problem by the zero point energy of
each
| partner canceling the other out? If so then, while it would resolve the
| above issue, the region where it kicks in would seem to be at an energy
| level above that to resolve the cosmological constant problem.

Volovik has some interesting ideas about this from his studies of superfluid
helium. You might want to check out what he has to say about it. He gives
some good reasons for why there is a near zero cosmological constant. I
don't know if I fully agree with them yet but they are compelling.
Basically, a stable quantum vacuum is non-gravitating. Without having to
resort to super-symmetry.

FrediFizzx