Do Free-Falling Charges in a Static Gravitational Field Radiate?

[Dickfore]

Someone had pointed out that the static field of a point charge may become inhomogeneous and/or time-dependent in a grav field.

I remember that a curved metric plays an analogous role to a(n inhomogeneous) dielectric constant. This means that the speed of propagation of em-waves is less than c. But, then, there arises the possibility of wakefields being created by charged particles traveling with speed higher than the corresponding phase velocity?

Is my conclusion correct?

 

[ApplePion]

"I think one can safely neglect self-coupling of the charge with its own electromagnetic field)"

In some places that is a good approximation, but this is definitely a place where you should not use such an approximation.

When a particle radiates energy, energy goes into the electromagnetic field. Unless there is a radiation reaction force on the particle, the field gets energy for "free", and energy will not be conserved.

 

[bcrowell]

ApplePion, you're posting in a thread that's been inactive since February.

There is a huge literature on this subject, dating back to the 60's. Here are some references:

C. Morette-DeWitt and B.S. DeWitt, "Falling Charges," Physics, 1,3-20 (1964), http://www.scribd.com/doc/100745033/Dewitt-1964

http://arxiv.org/abs/gr-qc/9303025 -- Parrott, 1993

http://arxiv.org/abs/physics/9910019 -- Harpaz and Soker, 1999

http://arxiv.org/abs/0905.2391 -- Gralla, Harte, and Wald, 2009

http://arxiv.org/abs/0806.0464 -- Grøn and Næss, 2008

http://arxiv.org/abs/gr-qc/0006037

http://arxiv.org/abs/gr-qc/9909035

Some expositions:

http://www.itp.uni-hannover.de/~giulini/Heraeus/Seminar475/Talks/Lyle.pdf

http://www.mathpages.com/home/kmath528/kmath528.htm

 

[ApplePion]

"ApplePion, you're posting in a thread that's been inactive since February."

So pretty much are you!

Best wishes.