Electromagnetic stress energy tensor

1. Jul 24, 2010

relativityfan

hi,

I would like to know if the contribution of some electromagnetic field through the electromagnetic stress energy tensor can decrease the intensity of gravity. it has negative components.

can it decrease pressure?

in such case, this would lead to some kind of relative antigravity like dark energy?

2. Jul 24, 2010

relativityfan

in the Reissner Nordstrom metric, the charge seems to generate some kind of antigravity near the curvature singularity and it decreases the radius of the event horizon. does that mean that electromagnetism generates there some kind of relative antigravity?

3. Jul 25, 2010

Altabeh

The contribution of electromagnetic field to the metric is positive in the Reissner Nordstrom metric as can be understood from the following perturbative terms appearing in the first and second components of the line-element:

$$g_{00}=1-2m/r+4\pi Ge^2/r^2c^4$$ and
$$g_{11}=1/g_{00}.$$

The electromagnetic field always produces a really tiny curvature unisonant with the curvature generated by the existence of matter and gravitational field. Antigravity just states that if a gravitating body has a negative total charge, then all the charged particles with the same charge sign would escape from gravity. But this has not been ever observed experimentally and usually is perdicted to be wrong because as a result of the electromagnetic field being really weak compared to the gravitational force, such interation wouldn't be possible and would indeed lead to big paradoxes inside the GR; one being the fact that gravity is an attractive force. Google "Göde Scientific Research Foundation" to get the newest news on this issue.

AB

4. Jul 25, 2010

relativityfan

in the Kerr metric the same applies near the curvature singularity with some kind of antigravity