# Collapse in gravitaion field

1. Mar 12, 2014

Hi,

I've know that accelerated charge generates electromagnetic radiation which eventually should cause the electron to crash in to the atom nuclear, until Bohr atom model.
Suppose that we have a mass which cause to gravitation field.
If this mass will be accelerated, will it radiate gravitational field? and furthermore, will it energy will be lost eventually (In this case I guess that Bohr's model is not relevant) ?

Thanks,

2. Mar 12, 2014

### UltrafastPED

People write articles on this topic such as "Electrodynamics of Radiating Charges": http://www.hindawi.com/journals/amp/2012/528631/ref/

"The radiation of a uniformly accelerated charge is beyond the horizon: A simple
derivation": http://arxiv.org/pdf/physics/0506049.pdf

"Hawking-Unruh Radiation and Radiation of a Uniformly Accelerated Charge":

This final paper, which takes into account quantum effects, provides the best explanation of the three.

For the Unruh effect, see: http://en.wikipedia.org/wiki/Unruh_effect

3. Mar 12, 2014

### dauto

Yes, it is believed that acceleration of masses may cause the production of gravitational waves. But so far experiments have failed to detect those waves.

4. Mar 12, 2014

### WannabeNewton

Hey Adam. You remember how the electric dipole radiation's angular distribution of power radiated comes from the second time derivative of the electric dipole moment of a charge distribution in the dipole approximation? Well for gravitational waves, using a similar approximation scheme, we find that the radiation comes from the third time derivative of the mass quadrupole moment of a mass distribution (the dipole moment doesn't contribute simply because of conservation of momentum). If a system is accelerated so as to yield a sufficiently dynamical mass quadrupole moment then yes there will be gravitational radiation and energy will be lost over time. But note that for most sources the amplitude and energy carried away will be orders of magnitude lower than what we could even hope to detect. Anything non-negligible in amplitude tends to be generated by extremely violent astrophysical events like non-spherical supernovae.